Internet Research Task Force (IRTF)                             A. Doria
Request for Comments: 5772                                           LTU
Category: Historic                                             E. Davies
ISSN: 2070-1721                                         Folly Consulting
                                                           F. Kastenholz
                                                        BBN Technologies
                                                           February 2010
Internet Research Task Force (IRTF)                             A. Doria
Request for Comments: 5772                                           LTU
Category: Historic                                             E. Davies
ISSN: 2070-1721                                         Folly Consulting
                                                           F. Kastenholz
                                                        BBN Technologies
                                                           February 2010

A Set of Possible Requirements for a Future Routing Architecture




The requirements for routing architectures described in this document were produced by two sub-groups under the IRTF Routing Research Group (RRG) in 2001, with some editorial updates up to 2006. The two sub-groups worked independently, and the resulting requirements represent two separate views of the problem and of what is required to fix the problem. This document may usefully serve as part of the recommended reading for anyone who works on routing architecture designs for the Internet in the future.


The document is published with the support of the IRTF RRG as a record of the work completed at that time, but with the understanding that it does not necessarily represent either the latest technical understanding or the technical consensus of the research group at the date of publication.

该文件在IRTF RRG的支持下发布,作为当时完成工作的记录,但有一项谅解,即该文件不一定代表发布之日研究小组的最新技术理解或技术共识。

Status of This Memo


This document is not an Internet Standards Track specification; it is published for the historical record.


This document defines a Historic Document for the Internet community. This document is a product of the Internet Research Task Force (IRTF). The IRTF publishes the results of Internet-related research and development activities. These results might not be suitable for deployment. This RFC represents the individual opinion(s) of one or more members of the Routing Research Group of the Internet Research Task Force (IRTF). Documents approved for publication by the IRSG are not a candidate for any level of Internet Standard; see Section 2 of RFC 5741.

本文档定义了互联网社区的历史文档。本文件是互联网研究工作组(IRTF)的产品。IRTF发布互联网相关研究和开发活动的结果。这些结果可能不适合部署。本RFC代表互联网研究任务组(IRTF)路由研究组一名或多名成员的个人意见。IRSG批准发布的文件不适用于任何级别的互联网标准;见RFC 5741第2节。

Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at


Copyright Notice


Copyright (c) 2010 IETF Trust and the persons identified as the document authors. All rights reserved.

版权所有(c)2010 IETF信托基金和确定为文件作者的人员。版权所有。

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents ( in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document.

本文件受BCP 78和IETF信托有关IETF文件的法律规定的约束(自本文件出版之日起生效。请仔细阅读这些文件,因为它们描述了您对本文件的权利和限制。

Table of Contents


   1. Background ......................................................4
   2. Results from Group A ............................................5
      2.1. Group A - Requirements for a Next Generation Routing and
           Addressing Architecture ....................................5
           2.1.1. Architecture ........................................6
           2.1.2. Separable Components ................................6
           2.1.3. Scalable ............................................7
           2.1.4. Lots of Interconnectivity ..........................10
           2.1.5. Random Structure ...................................10
           2.1.6. Multi-Homing .......................................11
           2.1.7. Multi-Path .........................................11
           2.1.8. Convergence ........................................12
           2.1.9. Routing System Security ............................14
           2.1.10. End Host Security .................................16
           2.1.11. Rich Policy .......................................16
           2.1.12. Incremental Deployment ............................19
           2.1.13. Mobility ..........................................19
           2.1.14. Address Portability ...............................20
           2.1.15. Multi-Protocol ....................................20
           2.1.16. Abstraction .......................................20
           2.1.17. Simplicity ........................................21
           2.1.18. Robustness ........................................21
           2.1.19. Media Independence ................................22
           2.1.20. Stand-Alone .......................................22
           2.1.21. Safety of Configuration ...........................23
           2.1.22. Renumbering .......................................23
           2.1.23. Multi-Prefix ......................................23
           2.1.24. Cooperative Anarchy ...............................23
           2.1.25. Network-Layer Protocols and Forwarding Model ......23
           2.1.26. Routing Algorithm .................................23
           2.1.27. Positive Benefit ..................................24
           2.1.28. Administrative Entities and the IGP/EGP Split .....24
      2.2. Non-Requirements ..........................................25
           2.2.1. Forwarding Table Optimization ......................25
   1. Background ......................................................4
   2. Results from Group A ............................................5
      2.1. Group A - Requirements for a Next Generation Routing and
           Addressing Architecture ....................................5
           2.1.1. Architecture ........................................6
           2.1.2. Separable Components ................................6
           2.1.3. Scalable ............................................7
           2.1.4. Lots of Interconnectivity ..........................10
           2.1.5. Random Structure ...................................10
           2.1.6. Multi-Homing .......................................11
           2.1.7. Multi-Path .........................................11
           2.1.8. Convergence ........................................12
           2.1.9. Routing System Security ............................14
           2.1.10. End Host Security .................................16
           2.1.11. Rich Policy .......................................16
           2.1.12. Incremental Deployment ............................19
           2.1.13. Mobility ..........................................19
           2.1.14. Address Portability ...............................20
           2.1.15. Multi-Protocol ....................................20
           2.1.16. Abstraction .......................................20
           2.1.17. Simplicity ........................................21
           2.1.18. Robustness ........................................21
           2.1.19. Media Independence ................................22
           2.1.20. Stand-Alone .......................................22
           2.1.21. Safety of Configuration ...........................23
           2.1.22. Renumbering .......................................23
           2.1.23. Multi-Prefix ......................................23
           2.1.24. Cooperative Anarchy ...............................23
           2.1.25. Network-Layer Protocols and Forwarding Model ......23
           2.1.26. Routing Algorithm .................................23
           2.1.27. Positive Benefit ..................................24
           2.1.28. Administrative Entities and the IGP/EGP Split .....24
      2.2. Non-Requirements ..........................................25
           2.2.1. Forwarding Table Optimization ......................25
           2.2.2. Traffic Engineering ................................25
           2.2.3. Multicast ..........................................25
           2.2.4. Quality of Service (QoS) ...........................26
           2.2.5. IP Prefix Aggregation ..............................26
           2.2.6. Perfect Safety .....................................26
           2.2.7. Dynamic Load Balancing .............................27
           2.2.8. Renumbering of Hosts and Routers ...................27
           2.2.9. Host Mobility ......................................27
           2.2.10. Backward Compatibility ............................27
   3. Requirements from Group B ......................................27
      3.1. Group B - Future Domain Routing Requirements ..............28
      3.2. Underlying Principles .....................................28
           3.2.1. Inter-Domain and Intra-Domain ......................29
           3.2.2. Influences on a Changing Network ...................29
           3.2.3. High-Level Goals ...................................31
      3.3. High-Level User Requirements ..............................35
           3.3.1. Organizational Users ...............................35
           3.3.2. Individual Users ...................................37
      3.4. Mandated Constraints ......................................38
           3.4.1. The Federated Environment ..........................39
           3.4.2. Working with Different Sorts of Networks ...........39
           3.4.3. Delivering Resilient Service .......................39
           3.4.4. When Will the New Solution Be Required? ............40
      3.5. Assumptions ...............................................40
      3.6. Functional Requirements ...................................42
           3.6.1. Topology ...........................................43
           3.6.2. Distribution .......................................44
           3.6.3. Addressing .........................................48
           3.6.4. Statistics Support .................................50
           3.6.5. Management Requirements ............................50
           3.6.6. Provability ........................................51
           3.6.7. Traffic Engineering ................................52
           3.6.8. Support for Middleboxes ............................54
      3.7. Performance Requirements ..................................54
      3.8. Backward Compatibility (Cutover) and Maintainability ......55
      3.9. Security Requirements .....................................56
      3.10. Debatable Issues .........................................57
           3.10.1. Network Modeling ..................................58
           3.10.2. System Modeling ...................................58
           3.10.3. One, Two, or Many Protocols .......................59
           3.10.4. Class of Protocol .................................59
           3.10.5. Map Abstraction ...................................59
           3.10.6. Clear Identification for All Entities .............60
           3.10.7. Robustness and Redundancy .........................60
           3.10.8. Hierarchy .........................................60
           3.10.9. Control Theory ....................................61
           3.10.10. Byzantium ........................................61
           3.10.11. VPN Support ......................................61
           2.2.2. Traffic Engineering ................................25
           2.2.3. Multicast ..........................................25
           2.2.4. Quality of Service (QoS) ...........................26
           2.2.5. IP Prefix Aggregation ..............................26
           2.2.6. Perfect Safety .....................................26
           2.2.7. Dynamic Load Balancing .............................27
           2.2.8. Renumbering of Hosts and Routers ...................27
           2.2.9. Host Mobility ......................................27
           2.2.10. Backward Compatibility ............................27
   3. Requirements from Group B ......................................27
      3.1. Group B - Future Domain Routing Requirements ..............28
      3.2. Underlying Principles .....................................28
           3.2.1. Inter-Domain and Intra-Domain ......................29
           3.2.2. Influences on a Changing Network ...................29
           3.2.3. High-Level Goals ...................................31
      3.3. High-Level User Requirements ..............................35
           3.3.1. Organizational Users ...............................35
           3.3.2. Individual Users ...................................37
      3.4. Mandated Constraints ......................................38
           3.4.1. The Federated Environment ..........................39
           3.4.2. Working with Different Sorts of Networks ...........39
           3.4.3. Delivering Resilient Service .......................39
           3.4.4. When Will the New Solution Be Required? ............40
      3.5. Assumptions ...............................................40
      3.6. Functional Requirements ...................................42
           3.6.1. Topology ...........................................43
           3.6.2. Distribution .......................................44
           3.6.3. Addressing .........................................48
           3.6.4. Statistics Support .................................50
           3.6.5. Management Requirements ............................50
           3.6.6. Provability ........................................51
           3.6.7. Traffic Engineering ................................52
           3.6.8. Support for Middleboxes ............................54
      3.7. Performance Requirements ..................................54
      3.8. Backward Compatibility (Cutover) and Maintainability ......55
      3.9. Security Requirements .....................................56
      3.10. Debatable Issues .........................................57
           3.10.1. Network Modeling ..................................58
           3.10.2. System Modeling ...................................58
           3.10.3. One, Two, or Many Protocols .......................59
           3.10.4. Class of Protocol .................................59
           3.10.5. Map Abstraction ...................................59
           3.10.6. Clear Identification for All Entities .............60
           3.10.7. Robustness and Redundancy .........................60
           3.10.8. Hierarchy .........................................60
           3.10.9. Control Theory ....................................61
           3.10.10. Byzantium ........................................61
           3.10.11. VPN Support ......................................61
           3.10.12. End-to-End Reliability ...........................62
           3.10.13. End-to-End Transparency ..........................62
   4. Security Considerations ........................................62
   5. IANA Considerations ............................................63
   6. Acknowledgments ................................................63
   7. Informative References .........................................65
           3.10.12. End-to-End Reliability ...........................62
           3.10.13. End-to-End Transparency ..........................62
   4. Security Considerations ........................................62
   5. IANA Considerations ............................................63
   6. Acknowledgments ................................................63
   7. Informative References .........................................65
1. Background
1. 出身背景

In 2001, the IRTF Routing Research Group (IRTF RRG) chairs, Abha Ahuja and Sean Doran, decided to establish a sub-group to look at requirements for inter-domain routing (IDR). A group of well-known routing experts was assembled to develop requirements for a new routing architecture. Their mandate was to approach the problem starting from a blank slate. This group was free to take any approach, including a revolutionary approach, in developing requirements for solving the problems they saw in inter-domain routing.

2001年,IRTF路由研究组(IRTF RRG)主席Abha Ahuja和Sean Doran决定成立一个小组,研究域间路由(IDR)的要求。一组著名的路由专家被召集起来,为新的路由架构开发需求。他们的任务是从一张白纸开始处理这个问题。这个团队可以自由地采取任何方法,包括革命性的方法,来开发解决域间路由问题的需求。

Simultaneously, an independent effort was started in Sweden with a similar goal. A team, calling itself Babylon, with participation from vendors, service providers, and academia assembled to understand the history of inter-domain routing, to research the problems seen by the service providers, and to develop a proposal of requirements for a follow-on to the current routing architecture. This group's remit required an evolutionary approach starting from current routing architecture and practice. In other words, the group limited itself to developing an evolutionary strategy. The Babylon group was later folded into the IRTF RRG as Sub-Group B to distinguish it from the original RRG Sub-Group A.

与此同时,瑞典也开始了一项独立的努力,目标与此类似。一个自称为巴比伦的团队,来自供应商、服务提供商和学术界,他们聚集在一起,了解域间路由的历史,研究服务提供商所看到的问题,并为当前路由架构的后续发展提出需求建议。该团队的职责要求从当前的路由架构和实践出发,采用一种渐进的方法。换句话说,该集团仅限于发展一种进化战略。巴比伦群后来被折叠成IRTF RRG,作为B亚群,以区别于原始RRG亚群A。

One of the questions that arose while the groups were working in isolation was whether there would be many similarities between their sets of requirements. That is, would the requirements that grew from a blank sheet of paper resemble those that started with the evolutionary approach? As can be seen from reading the two sets of requirements, there were many areas of fundamental agreement but some areas of disagreement.


There were suggestions within the RRG that the two teams should work together to create a single set of requirements. Since these requirements are only guidelines to future work, however, some felt that doing so would risk losing content without gaining any particular advantage. It is not as if any group, for example, the IRTF RRG or the IETF Routing Area, was expected to use these requirements as written and to create an architecture that met these requirements. Rather, the requirements were in practice strong

RRG内部建议两个团队合作创建一套单一的需求。然而,由于这些要求只是未来工作的指导方针,一些人认为这样做可能会导致内容丢失,而不会获得任何特殊优势。这并不是说任何组织,例如IRTF RRG或IETF路由区域,都会按照书面要求使用这些需求,并创建满足这些需求的体系结构。相反,这些要求在实践中非常严格

recommendations for a way to proceed in creating a new routing architecture. In the end, the decision was made to include the results of both efforts, side by side, in one document.


This document contains the two requirement sets produced by the teams. The text has received only editorial modifications; the requirements themselves have been left unaltered. Whenever the editors felt that conditions had changed in the few years since the text was written, an editors' note has been added to the text.


In reading this document, it is important to keep in mind that all of these requirements are suggestions, which are laid out to assist those interested in developing new routing architectures. It is also important to remember that, while the people working on these suggestions have done their best to make intelligent suggestions, there are no guarantees. So a reader of this document should not treat what it says as absolute, nor treat every suggestion as necessary. No architecture is expected to fulfill every "requirement". Hopefully, though, future architectures will consider what is offered in this document.


The IRTF RRG supported publication of this document as a historical record of the work completed on the understanding that it does not necessarily represent either the latest technical understanding or the technical consensus of the research group at the time of publication. The document has had substantial review by members of the two teams, other members of the IRTF RRG, and additional experts over the years.

IRTF RRG支持将本文件作为已完成工作的历史记录出版,但前提是,本文件不一定代表出版时研究小组的最新技术理解或技术共识。多年来,两个小组的成员、IRTF RRG的其他成员和其他专家对该文件进行了实质性审查。

Finally, this document does not make any claims that it is possible to have a practical solution that meets all the listed requirements.


2. Results from Group A
2. A组结果

This section presents the results of the work done by Sub-Group A of the IRTF RRG during 2001-2002. The work originally appeared under the title: "Requirements For a Next Generation Routing and Addressing Architecture" and was edited by Frank Kastenholz.

本节介绍了IRTF RRG A小组在2001-2002年期间所做工作的结果。这部作品最初的标题是:“下一代路由和寻址体系结构的需求”,由Frank Kastenholz编辑。

2.1. Group A - Requirements for a Next Generation Routing and Addressing Architecture

2.1. A组-下一代路由和寻址体系结构的要求

The requirements presented in this section are not presented in any particular order.


2.1.1. Architecture
2.1.1. 建筑学

The new routing and addressing protocols, data structures, and algorithms need to be developed from a clear, well thought-out, and documented architecture.


The new routing and addressing system must have an architectural specification that describes all of the routing and addressing elements, their interactions, what functions the system performs, and how it goes about performing them. The architectural specification does not go into issues such as protocol and data structure design.


The architecture should be agnostic with regard to specific algorithms and protocols.


Doing architecture before doing detailed protocol design is good engineering practice. This allows the architecture to be reviewed and commented upon, with changes made as necessary, when it is still easy to do so. Also, by producing an architecture, the eventual users of the protocols (the operations community) will have a better understanding of how the designers of the protocols meant them to be used.


2.1.2. Separable Components
2.1.2. 可分离成分

The architecture must place different functions into separate components.


Separating functions, capabilities, and so forth into individual components and making each component "stand alone" is generally considered by system architects to be "A Good Thing". It allows individual elements of the system to be designed and tuned to do their jobs "very well". It also allows for piecemeal replacement and upgrading of elements as new technologies and algorithms become available.


The architecture must have the ability to replace or upgrade existing components and to add new ones, without disrupting the remaining parts of the system. Operators must be able to roll out these changes and additions incrementally (i.e., no "flag days"). These abilities are needed to allow the architecture to evolve as the Internet changes.


The architecture specification shall define each of these components, their jobs, and their interactions.


Some thoughts to consider along these lines are:


o Making topology and addressing separate subsystems. This may allow highly optimized topology management and discovery without constraining the addressing structure or physical topology in unacceptable ways.

o 创建拓扑结构并寻址独立的子系统。这可能允许高度优化的拓扑管理和发现,而不会以不可接受的方式限制寻址结构或物理拓扑。

o Separate "fault detection and healing" from basic topology. From Mike O'Dell:

o 将“故障检测和修复”与基本拓扑分离。迈克·奥戴尔:

Historically the same machinery is used for both. While attractive for many reasons, the availability of exogenous topology information (i.e., the intended topology) should, it seems, make some tasks easier than the general case of starting with zero knowledge. It certainly helps with recovery in the case of constraint satisfaction. In fact, the intended topology is a powerful way to state certain kinds of policy. [ODell01]


o Making policy definition and application a separate subsystem, layered over the others.

o 使策略定义和应用程序成为一个独立的子系统,分层于其他子系统之上。

The architecture should also separate topology, routing, and addressing from the application that uses those components. This implies that applications such as policy definition, forwarding, and circuit and tunnel management are separate subsystems layered on top of the basic topology, routing, and addressing systems.


2.1.3. Scalable
2.1.3. 可伸缩

Scaling is the primary problem facing the routing and addressing architecture today. This problem must be solved and it must be solved for the long term.


The architecture must support a large and complex network. Ideally, it will serve our needs for the next 20 years. Unfortunately:


1. we do not know how big the Internet will grow over that time, and

1. 我们不知道互联网将在这段时间内增长到多大,以及

2. the architecture developed from these requirements may change the fundamental structure of the Internet and therefore its growth patterns. This change makes it difficult to predict future growth patterns of the Internet.

2. 根据这些需求开发的体系结构可能会改变互联网的基本结构,从而改变其增长模式。这种变化使得人们很难预测互联网未来的增长模式。

As a result, we can't quantify the requirement in any meaningful way. Using today's architectural elements as a mechanism for describing things, we believe that the network could grow to:


1. tens of thousands of ASs

1. 数万头驴

Editors' Note: As of 2005, this level had already been reached.


2. tens to hundreds of millions of prefixes, during the lifetime of this architecture.

2. 在这个体系结构的生命周期中,有数千万到数亿个前缀。

These sizes are given as a "flavor" for how we expect the Internet to grow. We fully believe that any new architecture may eliminate some current architectural elements and introduce new ones.


A new routing and addressing architecture designed for a specific network size would be inappropriate. First, the cost of routing calculations is based only in part on the number of ASs or prefixes in the network. The number and locations of the links in the network are also significant factors. Second, past predictions of Internet growth and topology patterns have proven to be wildly inaccurate, so developing an architecture to a specific size goal would at best be shortsighted.


Editors' Note: At the time of these meetings, the BGP statistics kept at sites such as either did not exist or had been running for only a few months. After 5 years of recording public Internet data trends in AS growth, routing table growth can be observed (past) with some short-term prediction. As each year of data collection continues, the ability to observe and predict trends improves. This architecture work pointed out the need for such statistics to improve future routing designs.


Therefore, we will not make the scaling requirement based on a specific network size. Instead, the new routing and addressing architecture should have the ability to constrain the increase in load (CPU, memory space and bandwidth, and network bandwidth) on ANY SINGLE ROUTER to be less than these specific functions:


1. The computational power and memory sizes required to execute the routing protocol software and to contain the tables must grow more slowly than hardware capabilities described by Moore's Law, doubling every 18 months. Other observations indicate that memory sizes double every 2 years or so.

1. 执行路由协议软件和包含表所需的计算能力和内存大小必须比摩尔定律描述的硬件能力增长得慢,每18个月翻一番。其他观察表明,大约每两年内存大小就会翻一番。

2. Network bandwidth and latency are some key constraints on how fast routing protocol updates can be disseminated (and therefore how fast the routing system can adapt to changes). Raw network bandwidth seems to quadruple every 3 years or so. However, it seems that there are some serious physics problems in going faster than 40 Gbit/s (OC768); we should not expect raw network

2. 网络带宽和延迟是影响路由协议更新传播速度(以及路由系统适应变化的速度)的一些关键约束。原始网络带宽似乎每3年左右就会翻两番。然而,当速度超过40gbit/s(OC768)时,似乎存在一些严重的物理问题;我们不应该期望原始网络

link speed to grow much beyond OC768. On the other hand, for economic reasons, large swathes of the core of the Internet will still operate at lower speeds, possibly as slow as DS3.


Editors' Note: Technology is running ahead of imagination and higher speeds are already common.


Furthermore, in some sections of the Internet, even lower speed links are found. Corporate access links are often T1, or slower. Low-speed radio links exist. Intra-domain links may be T1 or fractional-T1 (or slower).


Therefore, the architecture must not make assumptions about the bandwidth available.


3. The speeds of high-speed RAMs (Static RAMs (SRAMs), used for caches and the like) are growing, though slowly. Because of their use in caches and other very specific applications, these RAMs tend to be small, a few megabits, and the size of these RAMs is not increasing very rapidly.

3. 高速ram(用于缓存等的静态ram)的速度正在增长,尽管速度很慢。由于它们在缓存和其他非常特殊的应用中的使用,这些ram往往很小,只有几兆比特,而且这些ram的大小没有快速增长。

On the other hand, the speed of "large" memories (Dynamic RAMs (DRAMs)) is increasing even slower than that for the high-speed RAMs. This is because the development of these RAMs is driven by the PC market, where size is very important, and low speed can be made up for by better caches.


Memory access rates should not be expected to increase significantly.


Editors' Note: Various techniques have significantly increased memory bandwidth. 800 MHz is now possible, compared with less than 100 MHz in the year 2000. This does not, however, contradict the next paragraph, but rather just extends the timescales somewhat.


The growth in resources available to any one router will eventually slow down. It may even stop. Even so, the network will continue to grow. The routing and addressing architecture must continue to scale in even this extreme condition. We cannot continue to add more computing power to routers forever. Other strategies must be available. Some possible strategies are hierarchy, abstraction, and aggregation of topology information.


2.1.4. Lots of Interconnectivity
2.1.4. 大量的互联性

The new routing and addressing architecture must be able to cope with a high degree of interconnectivity in the Internet. That is, there are large numbers of alternate paths and routes among the various elements. Mechanisms are required to prevent this interconnectivity (and continued growth in interconnectivity) from causing tables, compute time, and routing protocol traffic to grow without bound. The "cost" to the routing system of an increase in complexity must be limited in scope; sections of the network that do not see, or do not care about, the complexity ought not pay the cost of that complexity.


Over the past several years, the Internet has seen an increase in interconnectivity. Individual end sites (companies, customers, etc.), ISPs, exchange points, and so on, all are connecting to more "other things". Companies multi-home to multiple ISPs, ISPs peer with more ISPs, and so on. These connections are made for many reasons, such as getting more bandwidth, increased reliability and availability, policy, and so on. However, this increased interconnectivity has a price. It leads to more scaling problems as it increases the number of AS paths in the networks.


Any new architecture must assume that the Internet will become a denser mesh. It must not assume, nor can it dictate, certain patterns or limits on how various elements of the network interconnect.


Another facet of this requirement is that there may be multiple valid, loop-free paths available to a destination. See Section 2.1.7 for a further discussion.


We wryly note that one of the original design goals of IP was to support a large, heavily interconnected network, which would be highly survivable (such as in the face of a nuclear war).


2.1.5. Random Structure
2.1.5. 随机结构

The routing and addressing architecture must not place any constraints on or make assumptions about the topology or connectedness of the elements comprising the Internet. The routing and addressing architecture must not presume any particular network structure. The network does not have a "nice" structure. In the past, we used to believe that there was this nice "backbone/tier-1/ tier-2/end-site" sort of hierarchy. This is not so. Therefore, any new architecture must not presume any such structure.


Some have proposed that a geographic addressing scheme be used, requiring exchange points to be situated within each geographic "region". There are many reasons why we believe this to be a bad approach, but those arguments are irrelevant. The main issue is that the routing architecture should not presume a specific network structure.


2.1.6. Multi-Homing
2.1.6. 多链路

The architecture must provide multi-homing for all elements of the Internet. That is, multi-homing of hosts, subnetworks, end-sites, "low-level" ISPs, and backbones (i.e., lots of redundant interconnections) must be supported. Among the reasons to multi-home are reliability, load sharing, and performance tuning.


The term "multi-homing" may be interpreted in its broadest sense -- one "place" has multiple connections or links to another "place".


The architecture must not limit the number of alternate paths to a multi-homed site.


When multi-homing is used, it must be possible to use one, some (more than one but less than all), or all of the available paths to the multi-homed site. The multi-homed site must have the ability to declare which path(s) are used and under what conditions (for example, one path may be declared "primary" and the other "backup" and to be used only when the primary fails).


A current problem in the Internet is that multi-homing leads to undue increases in the size of the BGP routing tables. The new architecture must support multi-homing without undue routing table growth.


2.1.7. Multi-Path
2.1.7. 多路径

As a corollary to multi-homing, the architecture must allow for multiple paths from a source to a destination to be active at the same time. These paths need not have the same attributes. Policies are to be used to disseminate the attributes and to classify traffic for the different paths.


There must be a rich "language" for specifying the rules for classifying the traffic and assigning classes of traffic to different paths (or prohibiting it from certain paths). The rules should allow traffic to be classified based upon, at least, the following:


o IPv6 FlowIDs,

o IPv6流ID,

o Diffserv Code Point (DSCP) values,

o 区分服务代码点(DSCP)值,

o source and/or destination prefixes, or

o 源和/或目标前缀,或

o random selections at some probability.

o 以某种概率随机选择。

A mechanism is needed that allows operators to plan and manage the traffic load on the various paths. To start, this mechanism can be semi-automatic or even manual. Eventually, it ought to become fully automatic.


When multi-path forwarding is used, options must be available to preserve packet ordering where appropriate (such as for individual TCP connections).


Please refer to Section 2.2.7 for a discussion of dynamic load-balancing and management over multiple paths.


2.1.8. Convergence
2.1.8. 汇聚

The speed of convergence (also called the "stabilization time") is the time it takes for a router's routing processes to reach a new, stable, "solution" (i.e., forwarding information base) after a change someplace in the network. In effect, what happens is that the output of the routing calculations stabilizes -- the Nth iteration of the software produces the same results as the N-1th iteration.


The speed of convergence is generally considered to be a function of the number of subnetworks in the network and the amount of connections between those networks. As either number grows, the time it takes to converge increases.


In addition, a change can "ripple" back and forth through the system. One change can go through the system, causing some other router to change its advertised connectivity, causing a new change to ripple through. These oscillations can take a while to work their way out of the network. It is also possible that these ripples never die out. In this situation, the routing and addressing system is unstable; it never converges.


Finally, it is more than likely that the routers comprising the Internet never converge simply because the Internet is so large and complex. Assume it takes S seconds for the routers to stabilize on a solution for any one change to the network. Also, assume that changes occur, on average, every C seconds. Because of the size and complexity of the Internet, C is now less than S. Therefore, if a


change, C1, occurs at time T, the routing system would stabilize at time T+S, but a new change, C2, will occur at time T+C, which is before T+S. The system will start processing the new change before it's done with the old.


This is not to say that all routers are constantly processing changes. The effects of changes are like ripples in a pond. They spread outward from where they occur. Some routers will be processing just C1, others C2, others both C1 and C2, and others neither.


We have two separate scopes over which we can set requirements with respect to convergence:


1. Single Change: In this requirement, a single change of any type (link addition or deletion, router failure or restart, etc.) is introduced into a stabilized system. No additional changes are introduced. The system must re-stabilize within some measure of bounded time. This requirement is a fairly abstract one as it would be impossible to test in a real network. Definition of the time constraints remains an open research issue.

1. 单一变更:在该要求中,任何类型的单一变更(链路添加或删除、路由器故障或重启等)都会引入稳定系统。没有引入其他更改。系统必须在一定的有界时间内重新稳定。这是一个相当抽象的要求,因为不可能在真实的网络中进行测试。时间限制的定义仍然是一个开放的研究问题。

2. System-Wide: Defining a single target for maximum convergence time for the real Internet is absurd. As we mentioned earlier, the Internet is large enough and diverse enough so that it is quite likely that new changes are introduced somewhere before the system fully digests old ones.

2. 全系统:为真正的互联网定义一个最大融合时间的单一目标是荒谬的。正如我们前面提到的,互联网足够大,足够多样化,因此很有可能在系统完全消化旧的变化之前,在某处引入新的变化。

So, the first requirement here is that there must be mechanisms to limit the scope of any one change's visibility and effects. The number of routers that have to perform calculations in response to a change is kept small, as is the settling time.


The second requirement is based on the following assumptions:


- the scope of a change's visibility and impact can be limited. That is, routers within that scope know of the change and recalculate their tables based on the change. Routers outside of the scope don't see it at all.

- 变更的可视性和影响范围是有限的。也就是说,该范围内的路由器知道更改,并根据更改重新计算其表。范围之外的路由器根本看不到它。

- Within any scope, S, network changes are constantly occurring and the average inter-change interval is Tc seconds.

- 在任何范围内,S、网络变化不断发生,平均变化间隔为Tc秒。

- There are Rs routers within scope S.

- 在S范围内有Rs路由器。

- A subset of the destinations known to the routers in S, Ds, are impacted by a given change.

- S、Ds中路由器已知的目的地子集受到给定更改的影响。

- We can state that for Z% of the changes, within Y% of Tc seconds after a change, C, X% of the Rs routers have their routes to Ds settled to a useful answer (useful meaning that packets can get to Ds, though perhaps not by the optimal path -- this allows some "hunting" for the optimal solution).

- 我们可以说明,对于Z%的变化,在变化后的Tc秒的Y%内,C,X%的Rs路由器将其到Ds的路由确定为一个有用的答案(有用的意思是数据包可以到达Ds,尽管可能不是通过最佳路径——这允许一些“搜索”最优解决方案)。

X, Y, and Z are yet to be defined. Their definition remains a research issue.

十、 Y和Z尚未定义。它们的定义仍然是一个研究问题。

This requirement implies that the scopes can be kept relatively small in order to minimize Rs and maximize Tc.


The growth rate of the convergence time must not be related to the growth rate of the Internet as a whole. This implies that the convergence time either:


1. not be a function of basic network elements (such as prefixes and links/paths), and/or

1. 不是基本网络元素(例如前缀和链接/路径)的函数,和/或

2. that the Internet be continuously divisible into chunks that limit the scope and effect of a change, thereby limiting the number of routers, prefixes, links, and so on, involved in the new calculations.

2. 互联网可以不断地被划分成若干块,这些块限制了变化的范围和影响,从而限制了新计算中涉及的路由器、前缀、链接等的数量。

2.1.9. Routing System Security
2.1.9. 路由系统安全

The security of the Internet's routing system is paramount. If the routing system is compromised or attacked, the entire Internet can fail. This is unacceptable. Any new architecture must be secure.


Architectures by themselves are not secure. It is the implementation of an architecture, its protocols, algorithms, and data structures that are secure. These requirements apply primarily to the implementation. The architecture must provide the elements that the implementation needs to meet these security requirements. Also, the architecture must not prevent these security requirements from being met.


Security means different things to different people. In order for this requirement to be useful, we must define what we mean by security. We do this by identifying the attackers and threats we wish to protect against. They are:


Masquerading The system, including its protocols, must be secure against intruders adopting the identity of other known, trusted elements of the routing system and then using that position of trust for carrying out other attacks. Protocols must use cryptographically strong authentication.


Denial-of-Service (DoS) Attacks The architecture and protocols should be secure against DoS attacks directed at the routers.


The new architecture and protocols should provide as much information as it can to allow administrators to track down sources of DoS and Distributed DOS (DDoS) attacks.


No Bad Data Any new architecture and protocols must provide protection against the introduction of bad, erroneous, or misleading data by attackers. Of particular importance, an attacker must not be able to redirect traffic flows, with the intent of:


o directing legitimate traffic away from a target, causing a denial-of-service attack by preventing legitimate data from reaching its destination,

o 引导合法流量远离目标,通过阻止合法数据到达其目的地而导致拒绝服务攻击,

o directing additional traffic (going to other destinations that are "innocent bystanders") to a target, causing the target to be overloaded, or

o 将额外流量(前往“无辜旁观者”的其他目的地)导向目标,导致目标超载,或

o directing traffic addressed to the target to a place where the attacker can copy, snoop, alter, or otherwise affect the traffic.

o 将指向目标的流量定向到攻击者可以复制、窥探、更改或以其他方式影响流量的位置。

Topology Hiding Any new architecture and protocols must provide mechanisms to allow network owners to hide the details of their internal topologies, while maintaining the desired levels of service connectivity and reachability.


Privacy By "privacy" we mean privacy of the routing protocol exchanges between routers.


When the routers are on point-to-point links, with routers at each end, there may not be any need to encrypt the routing protocol traffic as the possibility of a third party


intercepting the traffic is limited, though not impossible. We do believe, however, that it is important to have the ability to protect routing protocol traffic in two cases:


1. When the routers are on a shared network, it is possible that there are hosts on the network that have been compromised. These hosts could surreptitiously monitor the protocol traffic.

1. 当路由器位于共享网络上时,网络上可能存在已被破坏的主机。这些主机可以秘密监视协议流量。

2. When two routers are exchanging information "at a distance" (over intervening routers and, possibly, across administrative domain boundaries). In this case, the security of the intervening routers, links, and so on, cannot be assured. Thus, the ability to encrypt this traffic is important.

2. 当两个路由器“远距离”交换信息时(通过中间路由器,可能跨越管理域边界)。在这种情况下,无法保证介入路由器、链路等的安全性。因此,加密此流量的能力非常重要。

Therefore, we believe that the option to encrypt routing protocol traffic is required.


Data Consistency A router should be able to detect and recover from any data that is received from other routers that is inconsistent. That is, it must not be possible for data from multiple routers, none of which is malicious, to "break" another router.


Where security mechanisms are provided, they must use methods that are considered to be cryptographically secure (e.g., using cryptographically strong encryption and signatures -- no cleartext passwords!).


Use of security features should not be optional (except as required above). This may be "social engineering" on our part, but we believe it to be necessary. If a security feature is optional, the implementation of the feature must default to the "secure" setting.


2.1.10. End Host Security
2.1.10. 终端主机安全

The architecture must not prevent individual host-to-host communications sessions from being secured (i.e., it cannot interfere with things like IPsec).


2.1.11. Rich Policy
2.1.11. 富国政策

Before setting out policy requirements, we need to define the term. Like "security", "policy" means different things to different people. For our purposes, "policy" is the set of administrative influences that alter the path determination and next-hop selection procedures of the routing software.


The main motivators for influencing path and next-hop selection seem to be transit rules, business decisions, and load management.


The new architecture must support rich policy mechanisms. Furthermore, the policy definition and dissemination mechanisms should be separated from the network topology and connectivity dissemination mechanisms. Policy provides input to and controls the generation of the forwarding table and the abstraction, filtering, aggregation, and dissemination of topology information.


Note that if the architecture is properly divided into subsystems, then at a later time, new policy subsystems that include new features and capabilities could be developed and installed as needed.


We divide the general area of policy into two sub-categories: routing information and traffic control. Routing Information Policies control what routing information is disseminated or accepted, how it is disseminated, and how routers determine paths and next-hops from the received information. Traffic Control Policies determine how traffic is classified and assigned to routes.

我们将政策的一般领域分为两个子类:路由信息和流量控制。路由信息策略控制哪些路由信息被传播或接受,如何传播,以及路由器如何根据接收到的信息确定路径和下一跳。交通控制策略确定如何对交通进行分类并将其分配给路线。 Routing Information Policies 路由信息策略

There must be mechanisms to allow network administrators, operators, and designers to control receipt and dissemination of routing information. These controls include, but are not limited to:


- Selecting to which other routers routing information will be transmitted.

- 选择将向哪些其他路由器发送路由信息。

- Specifying the "granularity" and type of transmitted information. The length of IPv4 prefixes is an example of granularity.

- 指定传输信息的“粒度”和类型。IPv4前缀的长度是粒度的一个示例。

- Selection and filtering of topology and service information that is transmitted. This gives different "views" of internal structure and topology to different peers.

- 选择和过滤传输的拓扑和服务信息。这为不同的对等方提供了不同的内部结构和拓扑“视图”。

- Selecting the level of security and authenticity for transmitted information.

- 选择传输信息的安全性和真实性级别。

- Being able to cause the level of detail that is visible for some portion of the network to reduce the farther you get from that part of the network.

- 能够使网络某个部分可见的详细程度降低,从而使您离该部分网络越远。

- Selecting from whom routing information will be accepted. This control should be "provisional" in the sense of "accept routes from "foo" only if there are no others available".

- 选择将从谁处接受路由信息。这种控制应该是“临时的”,即“只有在没有其他可用的情况下才接受来自“foo”的路由”。

- Accepting or rejecting routing information based on the path the information traveled (using the current system as an example, this would be filtering routes based on an AS appearing anywhere in the AS path). This control should be "use only if there are no other paths available".

- 根据信息所经过的路径接受或拒绝路由信息(以当前系统为例,这将基于as路径中任何位置出现的as来过滤路由)。此控件应为“仅在没有其他可用路径时使用”。

- Selecting the desired level of granularity for received routing information (this would include, but is not limited to, things similar in nature to the prefix-length filters widely used in the current routing and addressing system).

- 为接收到的路由信息选择所需的粒度级别(这将包括但不限于与当前路由和寻址系统中广泛使用的前缀长度过滤器性质相似的内容)。

- Selecting the level of security and authenticity of received information in order for that information to be accepted.

- 选择接收信息的安全性和真实性级别,以便接受该信息。

- Determining the treatment of received routing information based on attributes supplied with the information.

- 根据随信息一起提供的属性确定对接收到的路由信息的处理。

- Applying attributes to routing information that is to be transmitted and then determining treatment of information (e.g., sending it "here" but not "there") based on those tags.

- 将属性应用于要传输的路由信息,然后根据这些标记确定信息的处理方式(例如,将其发送到“此处”,而不是“那里”)。

- Selection and filtering of topology and service information that is received.

- 选择和筛选接收到的拓扑和服务信息。 Traffic Control Policies 交通管制政策

The architecture should provide mechanisms that allow network operators to manage and control the flow of traffic. The traffic controls should include, but are not limited to:


- The ability to detect and eliminate congestion points in the network (by redirecting traffic around those points).

- 能够检测并消除网络中的拥塞点(通过重定向这些点周围的流量)。

- The ability to develop multiple paths through the network with different attributes and then assign traffic to those paths based on some discriminators within the packets (discriminators include, but are not limited to, IP addresses or prefixes, IPv6 flow ID, DSCP values, and MPLS labels).

- 通过网络开发具有不同属性的多条路径,然后根据数据包中的一些鉴别器(鉴别器包括但不限于IP地址或前缀、IPv6流ID、DSCP值和MPLS标签)将流量分配给这些路径的能力。

- The ability to find and use multiple, equivalent paths through the network (i.e., they would have the "same" attributes) and allocate traffic across the paths.

- 通过网络查找和使用多条等效路径(即,它们具有“相同”属性)并跨路径分配流量的能力。

- The ability to accept or refuse traffic based on some traffic classification (providing, in effect, transit policies).

- 基于某些交通分类(提供有效的交通政策)接受或拒绝交通的能力。

Traffic classification must at least include the source and destination IP addresses (prefixes) and the DSCP value. Other fields may be supported, such as:


* Protocol and port-based functions,

* 基于协议和端口的功能,

* DSCP/QoS (Quality of Service) tuple (such as ports),

* DSCP/QoS(服务质量)元组(如端口),

* Per-host operations (i.e., /32 s for IPv4 and /128 s for IPv6), and

* 每主机操作(即IPv4为/32秒,IPv6为/128秒),以及

* Traffic matrices (e.g., traffic from prefix X and to prefix Y).

* 流量矩阵(例如,从前缀X到前缀Y的流量)。

2.1.12. Incremental Deployment
2.1.12. 增量部署

The reality of the Internet is that there can be no Internet-wide cutover from one architecture and protocol to another. This means that any new architecture and protocol must be incrementally deployable; ISPs must be able to set up small sections of the new architecture, check it out, and then slowly grow the sections. Eventually, these sections will "touch" and "squeeze out" the old architecture.


The protocols that implement the architecture must be able to interoperate at "production levels" with currently existing routing protocols. Furthermore, the protocol specifications must define how the interoperability is done.


We also believe that sections of the Internet will never convert over to the new architecture. Thus, it is important that the new architecture and its protocols be able to interoperate with "old architecture" regions of the network indefinitely.


The architecture's addressing system must not force existing address allocations to be redone: no renumbering!


2.1.13. Mobility
2.1.13. 流动性

There are two kinds of mobility: host mobility and network mobility. Host mobility is when an individual host moves from where it was to where it is. Network mobility is when an entire network (or subnetwork) moves.


The architecture must support network-level mobility. Please refer to Section 2.2.9 for a discussion of host mobility.


Editors' Note: Since the time of this work, the Network Mobility (NEMO) extensions to Mobile-IP [RFC3963] to accommodate mobile networks have been developed.


2.1.14. Address Portability
2.1.14. 地址可移植性

One of the big "hot items" in the current Internet political climate is portability of IP addresses (both v4 and v6). The short explanation is that people do not like to renumber when changing connection point or provider and do not trust automated renumbering tools.


The architecture must provide complete address portability.


2.1.15. Multi-Protocol
2.1.15. 多协议

The Internet is expected to be "multi-protocol" for at least the next several years. IPv4 and IPv6 will co-exist in many different ways during a transition period. The architecture must be able to handle both IPv4 and IPv6 addresses. Furthermore, protocols that supplant IPv4 and IPv6 may be developed and deployed during the lifetime of the architecture. The architecture must be flexible and extensible enough to handle new protocols as they arise.


Furthermore, the architecture must not assume any given relationships between a topological element's IPv4 address and its IPv6 address. The architecture must not assume that all topological elements have IPv4 addresses/prefixes, nor can it assume that they have IPv6 addresses/prefixes.


The architecture should allow different paths to the same destination to be used for different protocols, even if all paths can carry all protocols.


In addition to the addressing technology, the architecture need not be restricted to only packet-based multiplexing/demultiplexing technology (such as IP); support for other multiplexing/ demultiplexing technologies may be added.


2.1.16. Abstraction
2.1.16. 抽象

The architecture must provide mechanisms for network designers and operators to:


o Group elements together for administrative control purposes,

o 出于管理控制目的,将元素组合在一起,

o Hide the internal structure and topology of those groupings for administrative and security reasons,

o 出于管理和安全原因,隐藏这些分组的内部结构和拓扑结构,

o Limit the amount of topology information that is exported from the groupings in order to control the load placed on external routers,

o 限制从分组导出的拓扑信息量,以控制外部路由器上的负载,

o Define rules for traffic transiting or terminating in the grouping.

o 定义分组中传输或终止流量的规则。

The architecture must allow the current Autonomous System structure to be mapped into any new abstraction schemes.


Mapping mechanisms, algorithms, and techniques must be specified.


2.1.17. Simplicity
2.1.17. 简单

The architecture must be simple enough so that someone who is extremely knowledgeable in routing and who is skilled at creating straightforward and simple explanations can explain all the important concepts in less than an hour.


This criterion has been chosen since developing an objective measure of complexity for an architecture can be very difficult and is out of scope for this document.


The requirement is that the routing architecture be kept as simple as possible. This requires careful evaluation of possible features and functions with a merciless weeding out of those that "might be nice" but are not necessary.


By keeping the architecture simple, the protocols and software used to implement the architecture are simpler. This simplicity in turn leads to:


1. Faster implementation of the protocols. If there are fewer bells and whistles, then there are fewer things that need to be implemented.

1. 更快地实现协议。如果钟声和口哨声越来越少,那么需要实施的事情就会越来越少。

2. More reliable implementations. With fewer components, there is less code, reducing bug counts, and fewer interactions between components that could lead to unforeseen and incorrect behavior.

2. 更可靠的实现。组件越少,代码就越少,bug数量也就越少,组件之间的交互也就越少,从而导致不可预见和不正确的行为。

2.1.18. Robustness
2.1.18. 健壮性

The architecture, and the protocols implementing it, should be robust. Robustness comes in many different flavors. Some considerations with regard to robustness include (but are not limited to):


o Continued correct operation in the face of:

o 在以下情况下继续正确操作:

* Defective (even malicious) trusted routers.

* 有缺陷(甚至恶意)的受信任路由器。

* Network failures. Whenever possible, valid alternate paths are to be found and used.

* 网络故障。只要可能,应找到并使用有效的备用路径。

o Failures must be localized. That is, the architecture must limit the "spread" of any adverse effects of a misconfiguration or failure. Badness must not spread.

o 故障必须本地化。也就是说,架构必须限制错误配置或故障的任何不利影响的“传播”。恶不能蔓延。

Of course, the general robustness principle of being liberal in what's accepted and conservative in what's sent must also be applied.


Original Editor's Note: Some of the contributors to this section have argued that robustness is an aspect of security. I have exercised editor's discretion by making it a separate section. The reason for this is that to too many people "security" means "protection from break-ins" and "authenticating and encrypting data". This requirement goes beyond those views.


2.1.19. Media Independence
2.1.19. 媒体独立性

While it is an article of faith that IP operates over a wide variety of media (such as Ethernet, X.25, ATM, and so on), IP routing must take an agnostic view toward any "routing" or "topology" services that are offered by the medium over which IP is operating. That is, the new architecture must not be designed to integrate with any media-specific topology management or routing scheme.


The routing architecture must assume, and must work over, the simplest possible media.


The routing and addressing architecture can certainly make use of lower-layer information and services, when and where available, and to the extent that IP routing wishes.


2.1.20. Stand-Alone
2.1.20. 独立

The routing architecture and protocols must not rely on other components of the Internet (such as DNS) for their correct operation. Routing is the fundamental process by which data "finds its way around the Internet" and most, if not all, of those other components rely on routing to properly forward their data. Thus, routing cannot rely on any Internet systems, services, or capabilities that in turn rely on routing. If it did, a dependency loop would result.


2.1.21. Safety of Configuration
2.1.21. 配置的安全性

The architecture, protocols, and standard implementation defaults must be such that a router installed "out of the box" with no configuration, etc., by the operators will not cause "bad things" to happen to the rest of the routing system (e.g., no dial-up customers advertising routes to 18/8!).


2.1.22. Renumbering
2.1.22. 重新编号

The routing system must allow topological entities to be renumbered.


2.1.23. Multi-Prefix
2.1.23. 多前缀

The architecture must allow topological entities to have multiple prefixes (or the equivalent under the new architecture).


2.1.24. Cooperative Anarchy
2.1.24. 合作无政府状态

As RFC 1726[RFC1726] states:

正如RFC 1726[RFC1726]所述:

A major contributor to the Internet's success is the fact that there is no single, centralized, point of control or promulgator of policy for the entire network. This allows individual constituents of the network to tailor their own networks, environments, and policies to suit their own needs. The individual constituents must cooperate only to the degree necessary to ensure that they interoperate.


This decentralization, called "cooperative anarchy", is still a key feature of the Internet today. The new routing architecture must retain this feature. There can be no centralized point of control or promulgator of policy for the entire Internet.


2.1.25. Network-Layer Protocols and Forwarding Model
2.1.25. 网络层协议和转发模型

For the purposes of backward compatibility, any new routing and addressing architecture and protocols must work with IPv4 and IPv6 using the traditional "hop-by-hop" forwarding and packet-based multiplex/demultiplex models. However, the architecture need not be restricted to these models. Additional forwarding and multiplex/ demultiplex models may be added.


2.1.26. Routing Algorithm
2.1.26. 路由算法

The architecture should not require a particular routing algorithm family. That is to say, the architecture should be agnostic about link-state, distance-vector, or path-vector routing algorithms.


2.1.27. Positive Benefit
2.1.27. 正效益

Finally, the architecture must show benefits in terms of increased stability, decreased operational costs, and increased functionality and lifetime, over the current schemes. This benefit must remain even after the inevitable costs of developing and debugging the new protocols, enduring the inevitable instabilities as things get shaken out, and so on.


2.1.28. Administrative Entities and the IGP/EGP Split
2.1.28. 行政实体和IGP/EGP拆分

We explicitly recognize that the Internet consists of resources under control of multiple administrative entities. Each entity must be able to manage its own portion of the Internet as it sees fit. Moreover, the constraints that can be imposed on routing and addressing on the portion of the Internet under the control of one administration may not be feasibly extended to cover multiple administrations. Therefore, we recognize a natural and inevitable split between routing and addressing that is under a single administrative control and routing and addressing that involves multiple administrative entities. Moreover, while there may be multiple administrative authorities, the administrative authority boundaries may be complex and overlapping, rather than being a strict hierarchy.


Furthermore, there may be multiple levels of administration, each with its own level of policy and control. For example, a large network might have "continental-level" administrations covering its European and Asian operations, respectively. There would also be that network's "inter-continental" administration covering the Europe-to-Asia links. Finally, there would be the "Internet" level in the administrative structure (analogous to the "exterior" concept in the current routing architecture).


Thus, we believe that the administrative structure of the Internet must be extensible to many levels (more than the two provided by the current IGP/EGP split). The interior/exterior property is not absolute. The interior/exterior property of any point in the network is relative; a point on the network is interior with respect to some points on the network and exterior with respect to others.


Administrative entities may not trust each other; some may be almost actively hostile toward each other. The architecture must accommodate these models. Furthermore, the architecture must not require any particular level of trust among administrative entities.


2.2. Non-Requirements
2.2. 非要求

The following are not required or are non-goals. This should not be taken to mean that these issues must not be addressed by a new architecture. Rather, addressing these issues or not is purely an optional matter for the architects.


2.2.1. Forwarding Table Optimization
2.2.1. 转发表优化

We believe that it is not necessary for the architecture to minimize the size of the forwarding tables (FIBs). Current memory sizes, speeds, and prices, along with processor and Application-specific Integrated Circuit (ASIC) capabilities allow forwarding tables to be very large, O(E6), and allow fast (100 M lookups/second) tables to be built with little difficulty.

我们认为架构没有必要最小化转发表(FIB)的大小。当前的内存大小、速度和价格,以及处理器和专用集成电路(ASIC)功能允许转发表非常大,O(E6),并允许轻松构建快速(100 M查找/秒)表。

2.2.2. Traffic Engineering
2.2.2. 交通工程

"Traffic engineering" is one of those terms that has become terribly overloaded. If one asks N people what traffic engineering is, one would get something like N! disjoint answers. Therefore, we elect not to require "traffic engineering", per se. Instead, we have endeavored to determine what the ultimate intent is when operators "traffic engineer" their networks and then make those capabilities an inherent part of the system.


2.2.3. Multicast
2.2.3. 多播

The new architecture is not designed explicitly to be an inter-domain multicast routing architecture. However, given the notable lack of a viable, robust, and widely deployed inter-domain multicast routing architecture, the architecture should not hinder the development and deployment of inter-domain multicast routing without an adverse effect on meeting the other requirements.


We do note however that one respected network sage [Clark91] has said (roughly):


When you see a bunch of engineers standing around congratulating themselves for solving some particularly ugly problem in networking, go up to them, whisper "multicast", jump back, and watch the fun begin...


2.2.4. Quality of Service (QoS)
2.2.4. 服务质量(QoS)

The architecture concerns itself primarily with disseminating network topology information so that routers may select paths to destinations and build appropriate forwarding tables. Quality of Service (QoS) is not a part of this function and we make no requirements with respect to QoS.


However, QoS is an area of great and evolving interest. It is reasonable to expect that in the not too distant future, sophisticated QoS facilities will be deployed in the Internet. Any new architecture and protocols should be developed with an eye toward these future evolutions. Extensibility mechanisms, allowing future QoS routing and signaling protocols to "piggy-back" on top of the basic routing system are desired.


We do require the ability to assign attributes to entities and then do path generation and selection based on those attributes. Some may call this QoS.


2.2.5. IP Prefix Aggregation
2.2.5. IP前缀聚合

There is no specific requirement that CIDR-style (Classless Inter-Domain Routing) IP prefix aggregation be done by the new architecture. Address allocation policies, societal pressure, and the random growth and structure of the Internet have all conspired to make prefix aggregation extraordinarily difficult, if not impossible. This means that large numbers of prefixes will be sloshing about in the routing system and that forwarding tables will grow quite big. This is a cost that we believe must be borne.


Nothing in this non-requirement should be interpreted as saying that prefix aggregation is explicitly prohibited. CIDR-style IP prefix aggregation might be used as a mechanism to meet other requirements, such as scaling.


2.2.6. Perfect Safety
2.2.6. 完全安全

Making the system impossible to misconfigure is, we believe, not required. The checking, constraints, and controls necessary to achieve this could, we believe, prevent operators from performing necessary tasks in the face of unforeseen circumstances.


However, safety is always a "good thing", and any results from research in this area should certainly be taken into consideration and, where practical, incorporated into the new routing architecture.


2.2.7. Dynamic Load Balancing
2.2.7. 动态负载平衡

History has shown that using the routing system to perform highly dynamic load balancing among multiple more-or-less-equal paths usually ends up causing all kinds of instability, etc., in the network. Thus, we do not require such a capability.


However, this is an area that is ripe for additional research, and some believe that the capability will be necessary in the future. Thus, the architecture and protocols should be "malleable" enough to allow development and deployment of dynamic load-balancing capabilities, should we ever figure out how to do it.


2.2.8. Renumbering of Hosts and Routers
2.2.8. 主机和路由器的重新编号

We believe that the routing system is not required to "do renumbering" of hosts and routers. That's an IP issue.


Of course, the routing and addressing architecture must be able to deal with renumbering when it happens.


2.2.9. Host Mobility
2.2.9. 主机移动性

In the Internet architecture, host mobility is handled on a per-host basis by a dedicated, Mobile-IP protocol [RFC3344]. Traffic destined for a mobile-host is explicitly forwarded by dedicated relay agents. Mobile-IP [RFC3344] adequately solves the host-mobility problem and we do not see a need for any additional requirements in this area. Of course, the new architecture must not impede or conflict with Mobile-IP.


2.2.10. Backward Compatibility
2.2.10. 向后兼容性

For the purposes of development of the architecture, we assume that there is a "clean slate". Unless specified in Section 2.1, there are no explicit requirements that elements, concepts, or mechanisms of the current routing architecture be carried forward into the new one.


3. Requirements from Group B
3. B组的要求

The following is the result of the work done by Sub-Group B of the IRTF RRG in 2001-2002. It was originally released under the title: "Future Domain Routing Requirements" and was edited by Avri Doria and Elwyn Davies.

以下是IRTF RRG B小组在2001-2002年所做工作的结果。它最初以“未来域路由需求”的标题发布,由Avri Doria和Elwyn Davies编辑。

3.1. Group B - Future Domain Routing Requirements
3.1. B组-未来域路由要求

It is generally accepted that there are major shortcomings in the inter-domain routing of the Internet today and that these may result in meltdown within an unspecified period of time. Remedying these shortcomings will require extensive research to tie down the exact failure modes that lead to these shortcomings and identify the best techniques to remedy the situation.


Reviewer's Note: Even in 2001, there was a wide difference of opinion across the community regarding the shortcomings of inter-domain routing. In the years between writing and publication, further analysis, changes in operational practice, alterations to the demands made on inter-domain routing, modifications made to BGP, and a recognition of the difficulty of finding a replacement may have altered the views of some members of the community.


Changes in the nature and quality of the services that users want from the Internet are difficult to provide within the current framework, as they impose requirements never foreseen by the original architects of the Internet routing system.


The kind of radical changes that have to be accommodated are epitomized by the advent of IPv6 and the application of IP mechanisms to private commercial networks that offer specific service guarantees beyond the best-effort services of the public Internet. Major changes to the inter-domain routing system are inevitable to provide an efficient underpinning for the radically changed and increasingly commercially-based networks that rely on the IP protocol suite.


3.2. Underlying Principles
3.2. 基本原则

Although inter-domain routing is seen as the major source of problems, the interactions with intra-domain routing, and the constraints that confining changes to the inter-domain arena would impose, mean that we should consider the whole area of routing as an integrated system. This is done for two reasons:


- Requirements should not presuppose the solution. A continued commitment to the current definitions and split between inter-domain and intra-domain routing would constitute such a presupposition. Therefore, this part of the document uses the name Future Domain Routing (FDR).

- 需求不应以解决方案为前提。继续遵守当前的定义并在域间和域内路由之间进行划分将构成这样一个前提。因此,文档的这一部分使用了未来域路由(FDR)的名称。

- It is necessary to understand the degree to which inter-domain and intra-domain routing are related within today's routing architecture.

- 在当今的路由体系结构中,有必要了解域间和域内路由的关联程度。

We are aware that using the term "domain routing" is already fraught with danger because of possible misinterpretation due to prior usage. The meaning of "domain routing" will be developed implicitly throughout the document, but a little advance explicit definition of the word "domain" is required, as well as some explanation on the scope of "routing".


This document uses "domain" in a very broad sense, to mean any collection of systems or domains that come under a common authority that determines the attributes defining, and the policies controlling, that collection. The use of "domain" in this manner is very similar to the concept of region that was put forth by John Wroclawski in his Metanet model [Wroclawski95]. The idea includes the notion that certain attributes will characterize the behavior of the systems within a domain and that there will be borders between domains. The idea of domain presented here does not presuppose that two domains will have the same behavior. Nor does it presuppose anything about the hierarchical nature of domains. Finally, it does not place restrictions on the nature of the attributes that might be used to determine membership in a domain. Since today's routing domains are an example of the concept of domains in this document, there has been no attempt to create a new term.

本文档在非常广泛的意义上使用了“域”,指的是属于共同权限的任何系统或域的集合,该权限决定了定义该集合的属性以及控制该集合的策略。以这种方式使用“域”与John Wroclawski在其元网模型[Wroclawski95]中提出的区域概念非常相似。该思想包括这样一个概念,即某些属性将表征域内系统的行为,域之间将存在边界。这里提出的域概念并不是假设两个域具有相同的行为。它也没有预先假定域的层次性。最后,它不会对可能用于确定域中成员身份的属性的性质设置限制。由于今天的路由域是本文档中域概念的一个示例,因此没有尝试创建一个新术语。

Current practice in routing-system design stresses the need to separate the concerns of the control plane and the forwarding plane in a router. This document will follow this practice, but we still use the term "routing" as a global portmanteau to cover all aspects of the system. Specifically, however, "routing" will be used to mean the process of discovering, interpreting, and distributing information about the logical and topological structure of the network.


3.2.1. Inter-Domain and Intra-Domain
3.2.1. 域间和域内

Throughout this section, the terms "intra-domain" and "inter-domain" will be used. These should be understood as relative terms. In all cases of domains, there will be a set of network systems that are within that domain; routing between these systems will be termed "intra-domain". In some cases there will be routing between domains, which will be termed "inter-domain". It is possible that the routing exchange between two network systems can be viewed as intra-domain from one perspective and as inter-domain from another perspective.


3.2.2. Influences on a Changing Network
3.2.2. 对不断变化的网络的影响

The development of the Internet is likely to be driven by a number of changes that will affect the organization and the usage of the network, including:


- Ongoing evolution of the commercial relationships between (connectivity) service providers, leading to changes in the way in which peering between providers is organized and the way in which transit traffic is routed.

- (连接性)服务提供商之间商业关系的持续演变,导致提供商之间的对等组织方式和中转流量路由方式发生变化。

- Requirements for traffic engineering within and between domains including coping with multiple paths between domains.

- 域内和域之间的流量工程要求,包括处理域之间的多条路径。

- Addition of a second IP addressing technique, in the form of IPv6.

- 以IPv6的形式添加第二种IP寻址技术。

- The use of VPNs and private address space with IPv4 and IPv6.

- 在IPv4和IPv6中使用VPN和专用地址空间。

- Evolution of the end-to-end principle to deal with the expanded role of the Internet, as discussed in [Blumenthal01]: this paper discusses the possibility that the range of new requirements, especially the social and techno-political ones that are being placed on the future, may compromise the Internet's original design principles. This might cause the Internet to lose some of its key features, in particular, its ability to support new and unanticipated applications. This discussion is linked to the rise of new stakeholders in the Internet, especially ISPs; new government interests; the changing motivations of the ever growing user base; and the tension between the demand for trustworthy overall operation and the inability to trust the behavior of individual users.

- 如[Blumenthal01]中所述,为应对互联网作用的扩大,端到端原则的演变:本文讨论了一系列新要求,特别是未来的社会和技术政治要求,可能会损害互联网的原始设计原则。这可能会导致互联网失去一些关键功能,特别是它支持新的和意外的应用程序的能力。这一讨论与互联网上新的利益相关者,特别是互联网服务提供商的崛起有关;新政府利益;不断增长的用户群不断变化的动机;以及对可信任的整体操作的需求与无法信任单个用户行为之间的紧张关系。

- Incorporation of alternative forwarding techniques such as the explicit routing (pipes) supplied by the MPLS [RFC3031] and GMPLS [RFC3471] environments.

- 采用替代转发技术,如MPLS[RFC3031]和GMPLS[RFC3471]环境提供的显式路由(管道)。

- Integration of additional constraints into route determination from interactions with other layers (e.g., Shared Risk Link Groups [InferenceSRLG]). This includes the concern that redundant routes should not fate-share, e.g., because they physically run in the same trench.

- 通过与其他层的交互(例如,共享风险链接组[推论SRLG]),将附加约束集成到路线确定中。这包括担心冗余路由不应共享命运,例如,因为它们实际运行在同一个沟渠中。

- Support for alternative and multiple routing techniques that are better suited to delivering types of content organized in ways other than into IP-addressed packets.

- 支持替代和多种路由技术,这些技术更适合于以IP寻址数据包以外的方式组织的内容类型的交付。

Philosophically, the Internet has the mission of transferring information from one place to another. Conceptually, this information is rarely organized into conveniently sized, IP-addressed packets, and the FDR needs to consider how the information (content) to be carried is identified, named, and addressed. Routing techniques can then be adapted to handle the expected types of content.


3.2.3. High-Level Goals
3.2.3. 高级别目标

This section attempts to answer two questions:


- What are we trying to achieve in a new architecture?

- 在一个新的体系结构中,我们试图实现什么?

- Why should the Internet community care?

- 互联网社区为什么要关心?

There is a third question that needs to be answered as well, but that has seldom been explicitly discussed:


- How will we know when we have succeeded?

- 我们怎么知道我们什么时候成功了? Providing a Routing System Matched to Domain Organization 提供与域组织匹配的路由系统

Many of today's routing problems are caused by a routing system that is not well matched to the organization and policies that it is trying to support. Our goal is to develop a routing architecture where even a domain organization that is not envisioned today can be served by a routing architecture that matches its requirements. We will know when this goal is achieved when the desired policies, rules, and organization can be mapped into the routing system in a natural, consistent, and easily understood way.

今天的许多路由问题都是由路由系统与它试图支持的组织和策略不匹配引起的。我们的目标是开发一个路由体系结构,在这个体系结构中,即使是今天还没有设想的领域组织,也可以由一个符合其需求的路由体系结构来提供服务。当所需的策略、规则和组织能够以自然、一致且易于理解的方式映射到路由系统中时,我们将知道这一目标何时实现。 Supporting a Range of Different Communication Services 支持一系列不同的通信服务

Today's routing protocols only support a single data forwarding service that is typically used to deliver a best-effort service in the public Internet. On the other hand, Diffserv for example, can construct a number of different bit transport services within the network. Using some of the per-domain behaviors (PDB)s that have been discussed in the IETF, it is possible to construct services such as Virtual Wire [DiffservVW] and Assured Rate [DiffservAR].


Providers today offer rudimentary promises about traffic handling in the network, for example, delay and long-term packet loss guarantees. As time goes on, this becomes even more relevant. Communicating the service characteristics of paths in routing protocols will be necessary in the near future, and it will be necessary to be able to route packets according to their service requirements.


Thus, a goal of this architecture is to allow adequate information about path service characteristics to be passed between domains and consequently, to allow the delivery of bit transport services other than the best-effort datagram connectivity service that is the current common denominator.

因此,该架构的目标是允许在域之间传递关于路径服务特征的足够信息,从而允许比特传输服务的交付,而不是作为当前公分母的尽力而为数据报连接服务。 Scalable Well Beyond Current Predictable Needs 可扩展性远远超出当前可预测的需求

Any proposed FDR system should scale beyond the size and performance we can foresee for the next ten years. The previous IDR proposal as implemented by BGP, has, with some massaging, held up for over ten years. In that time the Internet has grown far beyond the predictions that were implied by the original requirements.


Unfortunately, we will only know if we have succeeded in this goal if the FDR system survives beyond its design lifetime without serious massaging. Failure will be much easier to spot!

不幸的是,只有当FDR系统在没有严重按摩的情况下超过其设计寿命时,我们才能知道我们是否成功实现了这一目标。失败会更容易发现! Alternative Forwarding Mechanisms 替代转发机制

With the advent of circuit-based technologies (e.g., MPLS [RFC3031] and GMPLS [RFC3471]) managed by IP routers there are forwarding mechanisms other than the datagram service that need to be supported by the routing architecture.


An explicit goal of this architecture is to add support for forwarding mechanisms other then the current hop-by-hop datagram forwarding service driven by globally unique IP addresses.

此体系结构的明确目标是添加对转发机制的支持,而不是由全局唯一IP地址驱动的当前逐跳数据报转发服务。 Separation of Topology Map from Connectivity Service 拓扑图与连接服务的分离

It is envisioned that an organization can support multiple services within a single network. These services can, for example, be of different quality, of different connectivity type, or of different protocols (e.g., IPv4 and IPv6). For all these services, there may be common domain topology, even though the policies controlling the routing of information might differ from service to service. Thus, a goal with this architecture is to support separation between creation of a domain (or organization) topology map and service creation.

设想一个组织可以在一个网络中支持多个服务。例如,这些服务可以具有不同的质量、不同的连接类型或不同的协议(例如,IPv4和IPv6)。对于所有这些服务,可能存在公共域拓扑,即使控制信息路由的策略可能因服务而异。因此,此体系结构的目标是支持域(或组织)拓扑图的创建和服务创建之间的分离。 Separation between Routing and Forwarding 路由和转发之间的分离

The architecture of a router is composed of two main separable parts: control and forwarding. These components, while inter-dependent, perform functions that are largely independent of each other. Control (routing, signaling, and management) is typically done in software while forwarding typically is done with specialized ASICs or network processors.


The nature of an IP-based network today is that control and data protocols share the same network and forwarding regime. This may not always be the case in future networks, and we should be careful to avoid building in this sharing as an assumption in the FDR.


A goal of this architecture is to support full separation of control and forwarding, and to consider what additional concerns might be properly considered separately (e.g., adjacency management).

这种架构的目标是支持完全分离的控制和转发,并考虑什么额外的关注,可以适当考虑单独(例如,邻接管理)。 Different Routing Paradigms in Different Areas of the Same Network 同一网络不同区域的不同路由模式

A number of routing paradigms have been used or researched, in addition to the conventional shortest-path-by-hop-count paradigm that is the current mainstay of the Internet. In particular, differences in underlying transport networks may mean that other kinds of routing are more relevant, and the perceived need for traffic engineering will certainly alter the routing chosen in various domains.


Explicitly, one of these routing paradigms should be the current routing paradigm, so that the new paradigms will inter-operate in a backward-compatible way with today's system. This will facilitate a migration strategy that avoids flag days.

明确地说,其中一个路由范例应该是当前的路由范例,这样新的范例将以向后兼容的方式与今天的系统交互操作。这将有助于制定一种迁移策略,避免出现卖旗日。 Protection against Denial-of-Service and Other Security Attacks 防止拒绝服务和其他安全攻击

Currently, existence of a route to a destination effectively implies that anybody who can get a packet onto the network is entitled to use that route. While there are limitations to this generalization, this is a clear invitation to denial-of-service attacks. A goal of the FDR system should be to allow traffic to be specifically linked to whole or partial routes so that a destination or link resources can be protected from unauthorized use.


Editors' Note: When sections like this one and the previous ones on quality differentiation were written, the idea of separating traffic for security or quality was considered an unqualified advantage. Today, however, in the midst of active discussions on Network Neutrality, it is clear that such issues have a crucial policy component that also needs to be understood. These, and other similar issues, are open to further research.

编者按:当这一节和之前关于质量差异化的章节被编写时,为了安全或质量而分离流量的想法被认为是一个绝对的优势。然而,今天,在关于网络中立性的积极讨论中,很明显,这些问题有一个重要的政策组成部分,也需要理解。这些问题以及其他类似问题有待进一步研究。 Provable Convergence with Verifiable Policy Interaction 具有可验证策略交互的可证明收敛性

It has been shown both analytically, by Griffin, et al. (see [Griffin99]), and practically (see [RFC3345]) that BGP will not converge stably or is only meta-stable (i.e., will not re-converge in the face of a single failure) when certain types of policy constraint are applied to categories of network topology. The addition of policy to the basic distance-vector algorithm invalidates the proofs of convergence that could be applied to a policy-free implementation.

Griffin等人(见[Griffin 99])和实际(见[RFC3345])都表明,当某些类型的策略约束应用于网络拓扑类别时,BGP不会稳定收敛或仅是亚稳定的(即,在单一故障情况下不会重新收敛)。将策略添加到基本距离向量算法中会使可应用于无策略实现的收敛性证明无效。

It has also been argued that global convergence may no longer be a necessary goal and that local convergence may be all that is required.


A goal of the FDR should be to achieve provable convergence of the protocols used that may involve constraining the topologies and domains subject to convergence. This will also require vetting the policies imposed to ensure that they are compatible across domain boundaries and result in a consistent policy set.


Editors' Note: This requirement is very optimistic in that it implies that it is possible to get operators to cooperate even it is seen by them to be against their business practices. Though perhaps Utopian, this is a good goal.

编者按:这一要求非常乐观,因为它意味着即使运营商认为这违反了他们的商业惯例,他们也有可能进行合作。尽管这可能是一个乌托邦,但这是一个很好的目标。 Robustness Despite Errors and Failures 尽管存在错误和故障,但仍具有健壮性

From time to time in the history of the Internet, there have been occurrences where misconfigured routers have destroyed global connectivity.


A goal of the FDR is to be more robust to configuration errors and failures. This should probably involve ensuring that the effects of misconfiguration and failure can be confined to some suitable locality of the failure or misconfiguration.

FDR的目标是对配置错误和故障具有更强的鲁棒性。这可能包括确保错误配置和故障的影响可以限制在故障或错误配置的某个适当位置。 Simplicity in Management 管理简单

The policy work ([rap-charter02], [snmpconf-charter02], and [policy-charter02]) that has been done at IETF provides an architecture that standardizes and simplifies management of QoS. This kind of simplicity is needed in a Future Domain Routing architecture and its protocols.


A goal of this architecture is to make configuration and management of inter-domain routing as simple as possible.


Editors' Note: Snmpconf and rap are the hopes of the past. Today, configuration and policy hope is focused on netconf [netconf-charter].

编者按:Snmpconf和rap是过去的希望。今天,配置和政策希望集中在netconf[netconf宪章]上。 The Legacy of RFC 1126 RFC1126的遗产

RFC 1126 outlined a set of requirements that were used to guide the development of BGP. While the network has changed in the years since 1989, many of the same requirements remain. A future domain routing solution has to support, as its base requirement, the level of function that is available today. A detailed discussion of RFC 1126


and its requirements can be found in [RFC5773]. Those requirements, while specifically spelled out in that document, are subsumed by the requirements in this document.


3.3. High-Level User Requirements
3.3. 高级用户需求

This section considers the requirements imposed by the target audience of the FDR both in terms of organizations that might own networks that would use FDR, and the human users who will have to interact with the FDR.


3.3.1. Organizational Users
3.3.1. 组织用户

The organizations that own networks connected to the Internet have become much more diverse since RFC 1126 [RFC1126] was published. In particular, major parts of the network are now owned by commercial service provider organizations in the business of making profits from carrying data traffic.

自RFC 1126[RFC1126]出版以来,拥有连接到互联网的网络的组织变得更加多样化。特别是,网络的主要部分现在归商业服务提供商组织所有,从事从数据传输中获利的业务。 Commercial Service Providers 商业服务提供者

The routing system must take into account the commercial service provider's need for secrecy and security, as well as allowing them to organize their business as flexibly as possible.


Service providers will often wish to conceal the details of the network from other connected networks. So far as is possible, the routing system should not require the service providers to expose more details of the topology and capability of their networks than is strictly necessary.


Many service providers will offer contracts to their customers in the form of Service Level Agreements (SLAs). The routing system must allow the providers to support these SLAs through traffic engineering and load balancing as well as multi-homing, providing the degree of resilience and robustness that is needed.


Service providers can be categorized as:


- Global Service Providers (GSPs) whose networks have a global reach. GSPs may, and usually will, wish to constrain traffic between their customers to run entirely on their networks. GSPs will interchange traffic at multiple peering points with other GSPs, and they will need extensive policy-based controls to control the interchange of traffic. Peering may be through the use of dedicated private lines between the partners or, increasingly, through Internet Exchange Points.

- 网络覆盖全球的全球服务提供商(GSP)。GSP可能,而且通常希望限制客户之间的通信量,使其完全在其网络上运行。GSP将在多个对等点与其他GSP交换流量,他们将需要广泛的基于策略的控制来控制流量交换。对等可以通过合作伙伴之间的专用专线进行,或者越来越多地通过互联网交换点进行。

- National, or regional, Service Providers (NSPs) that are similar to GSPs but typically cover one country. NSPs may operate as a federation that provides similar reach to a GSP and may wish to be able to steer traffic preferentially to other federation members to achieve global reach.

- 与GSP类似但通常覆盖一个国家的国家或地区服务提供商(NSP)。NSPs可以作为一个联邦运行,提供与GSP类似的覆盖范围,并且可能希望能够优先于其他联邦成员引导交通,以实现全球覆盖。

- Local Internet Service Providers (ISPs) operate regionally. They will typically purchase transit capacity from NSPs or GSPs to provide global connectivity, but they may also peer with neighboring, and sometimes distant, ISPs.

- 本地互联网服务提供商(ISP)在区域内运营。他们通常会从NSP或GSP处购买运输能力,以提供全球连接,但他们也可能与相邻的、有时是遥远的ISP对等。

The routing system should be sufficiently flexible to accommodate the continually changing business relationships of the providers and the various levels of trustworthiness that they apply to customers and partners.


Service providers will need to be involved in accounting for Internet usage and monitoring the traffic. They may be involved in government action to tax the usage of the Internet, enforce social mores and intellectual property rules, or apply surveillance to the traffic to detect or prevent crime.

服务提供商需要参与计算互联网使用情况和监控流量。他们可能参与政府的行动,对互联网的使用征税,强制执行社会习俗和知识产权规则,或者对流量进行监控,以发现或预防犯罪。 Enterprises 企业

The leaves of the network domain graph are in many cases networks supporting a single enterprise. Such networks cover an enormous range of complexity. Some multi-national companies own networks that rival the complexity and reach of a GSP, whereas many fall into the Small Office-Home Office (SOHO) category. The routing system should allow simple and robust configuration and operation for the SOHO category, while effectively supporting the larger enterprise.


Enterprises are particularly likely to lack the capability to configure and manage a complex routing system, and every effort should be made to provide simple configuration and operation for such networks.


Enterprises will also need to be able to change their service provider with ease. While this is predominantly a naming and addressing issue, the routing system must be able to support seamless changeover; for example, if the changeover requires a change of address prefix, the routing system must be able to cope with a period when both sets of addresses are in use.


Enterprises will wish to be able to multi-home to one or more providers as one possible means of enhancing the resilience of their network.


Enterprises will also frequently need to control the trust that they place both in workers and external connections through firewalls and similar mid-boxes placed at their external connections.

企业还经常需要通过防火墙和放置在外部连接处的类似中间盒来控制对员工和外部连接的信任。 Domestic Networks 国内网络

Increasingly domestic, i.e., non-business home, networks are likely to be 'always on' and will resemble SOHO enterprises networks with no special requirements on the routing system.


The routing system must also continue to support dial-up users.

路由系统还必须继续支持拨号用户。 Internet Exchange Points 互联网交换点

Peering of service providers, academic networks, and larger enterprises is happening increasingly at specific Internet Exchange Points where many networks are linked together in a relatively small physical area. The resources of the exchange may be owned by a trusted third party or owned jointly by the connecting networks. The routing systems should support such exchange points without requiring the exchange point to either operate as a superior entity with every connected network logically inferior to it or by requiring the exchange point to be a member of one (or all) connected networks. The connecting networks have to delegate a certain amount of trust to the exchange point operator.

服务提供商、学术网络和大型企业的对等越来越多地发生在特定的互联网交换点,在这些交换点上,许多网络在一个相对较小的物理区域内连接在一起。交易所的资源可以由受信任的第三方拥有,也可以由连接网络共同拥有。路由系统应支持此类交换点,而无需交换点作为上级实体运行,且每个连接的网络在逻辑上都低于该交换点,或要求交换点成为一个(或所有)连接网络的成员。连接网络必须将一定数量的信任委托给交换点运营商。 Content Providers 内容提供商

Content providers are at one level a special class of enterprise, but the desire to deliver content efficiently means that a content provider may provide multiple replicated origin servers or caches across a network. These may also be provided by a separate content delivery service. The routing system should facilitate delivering content from the most efficient location.


3.3.2. Individual Users
3.3.2. 个人用户

This section covers the most important human users of the FDR and their expected interactions with the system.

本节介绍FDR最重要的人类用户及其与系统的预期交互。 All End Users 所有最终用户

The routing system must continue to deliver the current global connectivity service (i.e., any unique address to any other unique address, subject to policy constraints) that has always been the basic aim of the Internet.


End user applications should be able to request, or have requested on their behalf by agents and policy mechanisms, end-to-end communication services with QoS characteristics different from the best-effort service that is the foundation of today's Internet. It should be possible to request both a single service channel and a bundle of service channels delivered as a single entity.

终端用户应用程序应该能够通过代理和策略机制来请求或请求代理,端到端的通信服务具有不同于尽力而为服务的QoS特性,这是当今互联网的基础。应该可以请求单个服务通道和作为单个实体交付的服务通道包。 Network Planners 网络规划师

The routing system should allow network planners to plan and implement a network that can be proved to be stable and will meet their traffic engineering requirements.

路由系统应允许网络规划者规划和实施一个可以证明稳定并满足其流量工程要求的网络。 Network Operators 网络运营商

The routing system should, so far as is possible, be simple to configure, operate and troubleshoot, behave in a predictable and stable fashion, and deliver appropriate statistics and events to allow the network to be managed and upgraded in an efficient and timely fashion.

路由系统应尽可能简单地配置、操作和故障排除,以可预测和稳定的方式运行,并提供适当的统计数据和事件,以便以高效和及时的方式管理和升级网络。 Mobile End Users 移动终端用户

The routing system must support mobile end users. It is clear that mobility is becoming a predominant mode for network access.


3.4. Mandated Constraints
3.4. 强制约束

While many of the requirements to which the protocol must respond are technical, some aren't. These mandated constraints are those that are determined by conditions of the world around us. Understanding these requirements requires an analysis of the world in which these systems will be deployed. The constraints include those that are determined by:


- environmental factors,

- 环境因素,,

- geography,

- 地理

- political boundaries and considerations, and

- 政治边界和考虑因素,以及

- technological factors such as the prevalence of different levels of technology in the developed world compared to those in the developing or undeveloped world.

- 技术因素,如发达国家与发展中国家或不发达国家相比,不同技术水平的普及率。

3.4.1. The Federated Environment
3.4.1. 联邦环境

The graph of the Internet network, with routers and other control boxes as the nodes and communication links as the edges, is today partitioned administratively into a large number of disjoint domains.


A common administration may have responsibility for one or more domains that may or may not be adjacent in the graph.


Commercial and policy constraints affecting the routing system will typically be exercised at the boundaries of these domains where traffic is exchanged between the domains.


The perceived need for commercial confidentiality will seek to minimize the control information transferred across these boundaries, leading to requirements for aggregated information, abstracted maps of connectivity exported from domains, and mistrust of supplied information.


The perceived desire for anonymity may require the use of zero-knowledge security protocols to allow users to access resources without exposing their identity.


The requirements should provide the ability for groups of peering domains to be treated as a complex domain. These complex domains could have a common administrative policy.


3.4.2. Working with Different Sorts of Networks
3.4.2. 与不同类型的网络合作

The diverse Layer 2 networks, over which the Layer 3 routing system is implemented, have typically been operated totally independently from the Layer 3 network and often with their own routing mechanisms. Consideration needs to be given to the desirable degree and nature of interchange of information between the layers. In particular, the need for guaranteed robustness through diverse routing layers implies knowledge of the underlying networks.


Mobile access networks may also impose extra requirements on Layer 3 routing.


3.4.3. Delivering Resilient Service
3.4.3. 提供弹性服务

The routing system operates at Layer 3 in the network. To achieve robustness and resilience at this layer requires that, where multiple diverse routes are employed as part of delivering the resilience, the routing system at Layer 3 needs to be assured that the Layer 2 and lower routes are really diverse. The "diamond problem" is the


simplest form of this problem -- a Layer 3 provider attempting to provide diversity buys Layer 2 services from two separate providers who in turn buy Layer 1 services from the same provider:


                             Layer 3 service
                              /           \
                             /             \
                         Layer 2         Layer 2
                       Provider A      Provider B
                             \             /
                              \           /
                             Layer 1 Provider
                             Layer 3 service
                              /           \
                             /             \
                         Layer 2         Layer 2
                       Provider A      Provider B
                             \             /
                              \           /
                             Layer 1 Provider

Now, when the backhoe cuts the trench, the Layer 3 provider has no resilience unless he had taken special steps to verify that the trench wasn't common. The routing system should facilitate avoidance of this kind of trap.


Some work is going on to understand the sort of problems that stem from this requirement, such as the work on Shared Risk Link Groups [InferenceSRLG]. Unfortunately, the full generality of the problem requires diversity be maintained over time between an arbitrarily large set of mutually distrustful providers. For some cases, it may be sufficient for diversity to be checked at provisioning or route instantiation time, but this remains a hard problem requiring research work.


3.4.4. When Will the New Solution Be Required?
3.4.4. 何时需要新的解决方案?

There is a full range of opinion on this subject. An informal survey indicates that the range varies from 2 to 6 years. And while there are those, possibly outliers, who think there is no need for a new routing architecture as well as those who think a new architecture was needed years ago, the median seems to lie at around 4 years. As in all projections of the future, this is not provable at this time.


Editors' Note: The paragraph above was written in 2002, yet could be written without change in 2006. As with many technical predictions and schedules, the horizon has remained fixed through this interval.


3.5. Assumptions
3.5. 假设

In projecting the requirements for the Future Domain Routing, a number of assumptions have been made. The requirements set out should be consistent with these assumptions, but there are doubtless a number of other assumptions that are not explicitly articulated here:


1. The number of hosts today is somewhere in the area of 100 million. With dial-in, NATs, and the universal deployment of IPv6, this is likely to become up to 500 million users (see [CIDR]). In a number of years, with wireless accesses and different appliances attaching to the Internet, we are likely to see a couple of billion (10^9) "users" on the Internet. The number of globally addressable hosts is very much dependent on how common NATs will be in the future.

1. 今天的主机数量大约在1亿台左右。随着拨号、NAT和IPv6的普遍部署,这很可能成为5亿用户(参见[CIDR])。在若干年内,随着无线接入和不同的设备连接到互联网,我们可能会在互联网上看到数十亿(10^9)“用户”。全球可寻址主机的数量在很大程度上取决于未来NAT的普及程度。

2. NATs, firewalls, and other middle-boxes exist, and we cannot assume that they will cease being a presence in the networks.

2. NAT、防火墙和其他中间盒是存在的,我们不能假设它们将不再存在于网络中。

3. The number of operators in the Internet will probably not grow very much, as there is a likelihood that operators will tend to merge. However, as Internet-connectivity expands to new countries, new operators will emerge and then merge again.

3. 互联网运营商的数量可能不会有太大增长,因为运营商可能会倾向于合并。然而,随着互联网连接扩展到新的国家,新的运营商将出现,然后再次合并。

4. At the beginning of 2002, there are around 12000 registered ASs. With current use of ASs (e.g., multi-homing) the number of ASs could be expected to grow to 25000 in about 10 years [Broido02]. This is down from a previously reported growth rate of 51% per year [RFC3221]. Future growth rates are difficult to predict.

4. 2002年初,大约有12000头注册的ASs。随着目前ASs的使用(例如,多宿主),ASs的数量有望在大约10年内增长到25000头[Broidoo2]。这低于之前报告的每年51%的增长率[RFC3221]。未来的增长率很难预测。

Editors' Note: In the routing report table of August 2006, the total number of ASs present in the Internet Routing Table was 23000. In 4 years, this is substantial progress on the prediction of 25000 ASs. Also, there are significantly more ASs registered than are visibly active, i.e., in excess of 42000 in mid-2006. It is possible, however, that many are being used internally.


5. In contrast to the number of operators, the number of domains is likely to grow significantly. Today, each operator has different domains within an AS, but this also shows in SLAs and policies internal to the operator. Making this globally visible would create a number of domains; 10-100 times the number of ASs, i.e., between 100,000 and 1,000,000.

5. 与运算符的数量相比,域的数量可能会显著增加。如今,每个运营商在AS中都有不同的域,但这也体现在运营商内部的SLA和策略中。使其全球可见将创建许多域;ASs数量的10-100倍,即100000到1000000之间。

6. With more and more capacity at the edge of the network, the IP network will expand. Today, there are operators with several thousands of routers, but this is likely to be increased. Some domains will probably contain tens of thousands of routers.

6. 随着网络边缘的容量越来越大,IP网络将不断扩展。今天,有运营商拥有数千台路由器,但这可能会增加。一些域可能包含数以万计的路由器。

7. The speed of connections in the (fixed) access will technically be (almost) unconstrained. However, the cost for the links will not be negligible so that the apparent speed will be effectively bounded. Within a number of years, some will have multi-gigabit speed in the access.

7. 从技术上讲,(固定)接入的连接速度将(几乎)不受限制。然而,链路的成本将不可忽略,因此表观速度将有效限制。在若干年内,一些设备的接入速度将达到数千兆位。

8. At the same time, the bandwidth of wireless access still has a strict upper-bound. Within the foreseeable future each user will have only a tiny amount of resources available compared to fixed accesses (10 kbps to 2 Mbps for a Universal Mobile Telecommunications System (UMTS) with only a few achieving the higher figure as the bandwidth is shared between the active users in a cell and only small cells can actually reach this speed, but 11 Mbps or more for wireless LAN connections). There may also be requirements for effective use of bandwidth as low as 2.4 Kbps or lower, in some applications.

8. 同时,无线接入的带宽仍然有严格的上限。在可预见的未来,与固定接入(通用移动通信系统(UMTS)的10 kbps到2 Mbps)相比,每个用户仅有少量可用资源由于带宽在小区中的活跃用户之间共享,只有少数几个小区达到了更高的速度,而且只有小的小区才能达到这个速度,但无线局域网连接的速度为11 Mbps或更高)。在某些应用中,可能还需要有效使用低至2.4 Kbps或更低的带宽。

9. Assumptions 7 and 8 taken together suggest a minimum span of bandwidth between 2.4 kbps to 10 Gbps.

9. 假设7和8加在一起表明带宽的最小跨度在2.4 kbps到10 Gbps之间。

10. The speed in the backbone has grown rapidly, and there is no evidence that the growth will stop in the coming years. Terabit-speed is likely to be the minimum backbone speed in a couple of years. The range of bandwidths that need to be represented will require consideration on how to represent the values in the protocols.

10. 主干网的增长速度很快,没有证据表明这种增长会在未来几年停止。太比特速度可能是几年内的最低主干速度。需要表示的带宽范围需要考虑如何表示协议中的值。

11. There have been discussions as to whether Moore's Law will continue to hold for processor speed. If Moore's Law does not hold, then communication circuits might play a more important role in the future. Also, optical routing is based on circuit technology, which is the main reason for taking "circuits" into account when designing an FDR.

11. 关于摩尔定律是否会继续适用于处理器速度,已经有过讨论。如果摩尔定律不成立,那么通信电路在未来可能扮演更重要的角色。此外,光路由基于电路技术,这是设计FDR时考虑“电路”的主要原因。

12. However, the datagram model still remains the fundamental model for the Internet.

12. 然而,数据报模型仍然是互联网的基本模型。

13. The number of peering points in the network is likely to grow, as multi-homing becomes important. Also, traffic will become more locally distributed, which will drive the demand for local peering.

13. 随着多归属变得越来越重要,网络中的对等点数量可能会增加。此外,流量将变得更加本地分布,这将推动对本地对等的需求。

Editors' Note: On the other hand, peer-to-peer networking may shift the balance in demand for local peering.


14. The FDR will achieve the same degree of ubiquity as the current Internet and IP routing.

14. FDR将实现与当前互联网和IP路由相同程度的普遍性。

3.6. Functional Requirements
3.6. 功能要求

This section includes a detailed discussion of new requirements for a Future Domain Routing architecture. The nth requirement carries the label "R(n)". As discussed in Section, a new architecture


must build upon the requirements of the past routing framework and must not reduce the functionality of the network. A discussion and analysis of the RFC 1126 requirements can be found in [RFC5773].

必须建立在过去路由框架的要求之上,并且不得降低网络的功能。有关RFC 1126要求的讨论和分析,请参见[RFC5773]。

3.6.1. Topology
3.6.1. 拓扑学 Routers Should Be Able to Learn and to Exploit the Domain Topology 路由器应该能够学习和利用域拓扑

R(1) Routers must be able to acquire and hold sufficient information on the underlying topology of the domain to allow the establishment of routes on that topology.


R(2) Routers must have the ability to control the establishment of routes on the underlying topology.


R(3) Routers must be able, where appropriate, to control Sub-IP mechanisms to support the establishment of routes.


The OSI Inter-Domain Routing Protocol (IDRP) [ISO10747] allowed a collection of topologically related domains to be replaced by an aggregate domain object, in a similar way to the Nimrod [Chiappa02] domain hierarchies. This allowed a route to be more compactly represented by a single collection instead of a sequence of individual domains.


R(4) Routers must, where appropriate, be able to construct abstractions of the topology that represent an aggregation of the topological features of some area of the topology.

R(4)在适当的情况下,路由器必须能够构造拓扑的抽象,这些抽象表示拓扑某个区域的拓扑特征的集合。 The Same Topology Information Should Support Different Path Selection Ideas 相同的拓扑信息应支持不同的路径选择思想

The same topology information needs to provide the more flexible spectrum of path selection methods that we might expect to find in a future Internet, including distributed techniques such as hop-by-hop, shortest path, local optimization constraint-based, class of service, source address routing, and destination address routing, as well as the centralized, global optimization constraint-based "traffic engineering" type. Allowing different path selection techniques will produce a much more predictable and comprehensible result than the "clever tricks" that are currently needed to achieve the same results. Traffic engineering functions need to be combined.


R(5) Routers must be capable of supporting a small number of different path selection algorithms.

R(5)路由器必须能够支持少量不同的路径选择算法。 Separation of the Routing Information Topology from the Data Transport Topology 路由信息拓扑与数据传输拓扑的分离

R(6) The controlling network may be logically separate from the controlled network.


The two functional "planes" may physically reside in the same nodes and share the same links, but this is not the only possibility, and other options may sometimes be necessary. An example is a pure circuit switch (that cannot see individual IP packets) combined with an external controller. Another example may be multiple links between two routers, where all the links are used for data forwarding but only one is used for carrying the routing session.


3.6.2. Distribution
3.6.2. 分配 Distribution Mechanisms 分配机制

R(7) Relevant changes in the state of the network, including modifications to the topology and changes in the values of dynamic capabilities, must be distributed to every entity in the network that needs them, in a reliable and trusted way, at the earliest appropriate time after the changes have occurred.


R(8) Information must not be distributed outside areas where it is needed, or believed to be needed, for the operation of the routing system.


R(9) Information must be distributed in such a way that it minimizes the load on the network, consistent with the required response time of the network to changes.

R(9)信息的分布方式必须使网络负载最小化,与网络对变化的响应时间一致。 Path Advertisement 路径广告

R(10) The router must be able to acquire and store additional static and dynamic information that relates to the capabilities of the topology and its component nodes and links and that can subsequently be used by path selection methods.


The inter-domain routing system must be able to advertise more kinds of information than just connectivity and domain paths.


R(11) The routing system must support service specifications, e.g., the Service Level Specifications (SLSs) developed by the Differentiated Services working group [RFC3260].


Careful attention should be paid to ensuring that the distribution of additional information with path advertisements remains scalable as domains and the Internet get larger, more numerous, and more diversified.


R(12) The distribution mechanism used for distributing network state information must be scalable with respect to the expected size of domains and the volume and rate of change of dynamic state that can be expected.


The combination of R(9) and R(12) may result in a compromise between the responsiveness of the network to change and the overhead of distributing change notifications. Attempts to respond to very rapid changes may damage the stability of the routing system.


Possible examples of additional capability information that might be carried include:


- QoS information

- 服务质量信息

To allow an ISP to sell predictable end-to-end QoS service to any destination, the routing system should have information about the end-to-end QoS. This means that:


R(13) The routing system must be able to support different paths for different services.


R(14) The routing system must be able to forward traffic on the path appropriate for the service selected for the traffic, either according to an explicit marking in each packet (e.g., MPLS labels, Diffserv Per-Hop Behaviors (PHBs) or DSCP values) or implicitly (e.g., the physical or logical port on which the traffic arrives).


R(15) The routing system should also be able to carry information about the expected (or actually, promised) characteristics of the entire path and the price for the service.


(If such information is exchanged at all between network operators today, it is through bilateral management interfaces, and not through the routing protocols.)


This would allow for the operator to optimize the choice of path based on a price/performance trade-off.


In addition to providing dynamic QoS information, the system should be able to use static class-of-service information.


- Security information

- 安全信息

Security characteristics of other domains referred to by advertisements can allow the routing entity to make routing decisions based on political concerns. The information itself is assumed to be secure so that it can be trusted.


- Usage and cost information

- 使用和成本信息

Usage and cost information can be used for billing and traffic engineering. In order to support cost-based routing policies for customers (i.e., peer ISPs), information such as "traffic on this link or path costs XXX per Gigabyte" needs to be advertised, so that the customer can choose a more or a less expensive route.

使用情况和成本信息可用于计费和流量工程。为了支持客户(即对等ISP)基于成本的路由策略,需要公布诸如“此链路上的流量或路径成本为每GB XXX”之类的信息,以便客户可以选择成本更高或更低的路由。

- Monitored performance

- 监控性能

Performance information such as delay and drop frequency can be carried. (This may only be suitable inside a domain because of trust considerations.) This should support at least the kind of delay-bound contractual terms that are currently being offered by service providers. Note that these values refer to the outcome of carrying bits on the path, whereas the QoS information refers to the proposed behavior that results in this outcome.


- Multicast information

- 多播信息

R(16) The routing system must provide information needed to create multicast distribution trees. This information must be provided for one-to-many distribution trees and should be provided for many-to-many distribution trees.


The actual construction of distribution trees is not necessarily done by the routing system.

配电树的实际构造不一定由路由系统完成。 Stability of Routing Information 路由信息的稳定性

R(17) The new network architecture must be stable without needing global convergence, i.e., convergence is a local property.


The degree to which this is possible and the definition of "local" remain research topics. Restricting the requirement for convergence to localities will have an effect on all of the other requirements in this section.


R(18) The distribution and the rate of distribution of changes must not affect the stability of the routing information. For example, commencing redistribution of a change before the previous one has settled must not cause instability.

R(18)变化的分布和分布率不得影响路由信息的稳定性。例如,在前一个变更解决之前开始重新分配变更不得导致不稳定。 Avoiding Routing Oscillations 避免路由振荡

R(19) The routing system must minimize oscillations in route advertisements.

R(19)路由系统必须最小化路由广告中的振荡。 Providing Loop-Free Routing and Forwarding 提供无环路路由和转发

In line with the separation of routing and forwarding concerns:


R(20) The distribution of routing information must be, so far as is possible, loop-free.


R(21) The forwarding information created from this routing information must seek to minimize persistent loops in the data-forwarding paths.


It is accepted that transient loops may occur during convergence of the protocol and that there are trade-offs between loop avoidance and global scalability.

在协议的收敛过程中可能会出现瞬态循环,并且在避免循环和全局可伸缩性之间存在权衡。 Detection, Notification, and Repair of Failures 故障的检测、通知和修复

R(22) The routing system must provide means for detecting failures of node equipment or communication links.


R(23) The routing system should be able to coordinate failure indications from Layer 3 mechanisms, from nodal mechanisms built into the routing system, and from lower-layer mechanisms that propagate up to Layer 3 in order to determine the root cause of the failure. This will allow the routing system to react correctly to the failure by activating appropriate mitigation and repair mechanisms if required, while ensuring that it does not react if lower-layer repair mechanisms are able to repair or mitigate the fault.


Most Layer 3 routing protocols have utilized keepalives or "hello" protocols as a means of detecting failures at Layer 3. The keepalive mechanisms are often complemented by analog mechanisms (e.g., laser-light detection) and hardware mechanisms (e.g., hardware/software watchdogs) that are built into routing nodes and communication links. Great care must be taken to make the best possible use of the various failure repair methods available while ensuring that only one repair mechanism at a time is allowed to repair any given fault.


Interactions between, for example, fast reroute mechanisms at Layer 3 and Synchronous Optical Network/Synchronous Digital Hierarchy (SONET/ SDH) repair at Layer 1 are highly undesirable and are likely to cause problems in the network.


R(24) Where a network topology and routing system contains multiple fault repair mechanisms, the responses of these systems to a detected failure should be coordinated so that the fault is repaired by the most appropriate means, and no extra repairs are initiated.


R(25) Where specialized packet exchange mechanisms (e.g., Layer 3 keepalive or "hello" protocol mechanisms) are used to detect failures, the routing system must allow the configuration of the rate of transmission of these keepalives. This must include the capability to turn them off altogether for links that are deliberately broken when no real user or control traffic is present (e.g., ISDN links).


This will allow the operator to compromise between the speed of failure detection and the proportion of link bandwidth dedicated to failure detection.


3.6.3. Addressing
3.6.3. 寻址 Support Mix of IPv4, IPv6, and Other Types of Addresses 支持IPv4、IPv6和其他类型地址的混合

R(26) The routing system must support a mix of different kinds of addresses.


This mix will include at least IPv4 and IPv6 addresses, and preferably various types of non-IP addresses, too. For instance, networks like SDH/SONET and Wavelength Division Multiplexing (WDM) may prefer to use non-IP addresses. It may also be necessary to support multiple sets of "private" (e.g., RFC 1918) addresses when dealing with multiple customer VPNs.

这种混合将至少包括IPv4和IPv6地址,最好也包括各种类型的非IP地址。例如,像SDH/SONET和波分复用(WDM)这样的网络可能更喜欢使用非IP地址。在处理多个客户VPN时,可能还需要支持多组“专用”(例如RFC 1918)地址。

R(27) The routing system should support the use of a single topology representation to generate routing and forwarding tables for multiple address families on the same network.


This capability would minimize the protocol overhead when exchanging routes.

此功能将使交换路由时的协议开销最小化。 Support for Domain Renumbering/Readdressing 支持域重新编号/重新排序

R(28) If a domain is subject to address reassignment that would cause forwarding interruption, then the routing system should support readdressing (e.g., when a new prefix is given to an old network, and the change is known in advance) by maintaining routing during the changeover period [RFC2071] [RFC2072].

R(28)如果域受到地址重新分配的影响,这将导致转发中断,那么路由系统应该通过在切换期间维护路由[RFC2071][RFC2072]来支持重新调整(例如,当一个新的前缀被赋予一个旧的网络时,并且改变是预先知道的)。 Multicast and Anycast 多播和选播

R(29) The routing system must support multicast addressing, both within a domain and across multiple domains.


R(30) The routing system should support anycast addressing within a domain. The routing system may support anycast addressing across domains.


An open question is whether it is possible or useful to support anycast addressing between cooperating domains.

一个悬而未决的问题是,支持协作域之间的选播寻址是否可能或有用。 Address Scoping 地址范围

R(31) The routing system must support scoping of unicast addresses, and it should support scoping of multicast and anycast address types.


The unicast address scoping that is being designed for IPv6 does not seem to cause any special problems for routing. IPv6 inter-domain routing handles only IPv6 global addresses, while intra-domain routing also needs to be aware of the scope of private addresses.


Editors' Note: the original reference was to site-local addresses, but these have been deprecated by the IETF. Link-local addresses are never routed at all.


More study may be needed to identify the requirements and solutions for scoping in a more general sense and for scoping of multicast and anycast addresses.

可能需要进行更多的研究,以确定更一般意义上的范围界定以及多播和选播地址范围界定的要求和解决方案。 Mobility Support 机动保障

R(32) The routing system must support system mobility. The term "system" includes anything from an end system to an entire domain.


We observe that the existing solutions based on renumbering and/or tunneling are designed to work with the current routing, so they do not add any new requirements to future routing. But the requirement is general, and future solutions may not be restricted to the ones we have today.


3.6.4. Statistics Support
3.6.4. 统计支持

R(33) Both the routing and forwarding parts of the routing system must maintain statistical information about the performance of their functions.


3.6.5. Management Requirements
3.6.5. 管理要求

While the tools of management are outside the scope of routing, the mechanisms to support the routing architecture and protocols are within scope.


R(34) Mechanisms to support Operational, Administrative, and Management control of the routing architecture and protocols must be designed into the original fabric of the architecture.

R(34)支持路由架构和协议的操作、管理和管理控制的机制必须设计到架构的原始结构中。 Simple Policy Management 简单策略管理

The basic aims of this specification are:


- to require less manual configuration than today, and

- 需要比现在更少的手动配置,以及

- to satisfy the requirements for both easy handling and maximum control. That is:

- 以满足易于操作和最大控制的要求。即:

- All the information should be available,

- 所有信息都应可用,

- but should not be visible except for when necessary.

- 但除非必要,否则不应可见。

- Policies themselves should be advertised and not only the result of policy, and

- 应宣传政策本身,而不仅仅是政策的结果,以及

- policy-conflict resolution must be provided.

- 必须提供政策冲突解决方案。

R(35) The routing system must provide management of the system by means of policies. For example, policies that can be expressed in terms of the business and services implemented on the network and reflect the operation of the network in terms of the services affected.


Editors' Note: This requirement is optimistic in that it implies that it is possible to get operators to cooperate even if it is seen by them to be against their business practices.


R(36) The distribution of policies must be amenable to scoping to protect proprietary policies that are not relevant beyond the local set of domains.

R(36)策略的分发必须服从范围界定,以保护在本地域集合之外不相关的专有策略。 Startup and Maintenance of Routers 路由器的启动与维护

A major problem in today's networks is the need to perform initial configuration on routers from a local interface before a remote management system can take over. It is not clear that this imposes any requirements on the routing architecture beyond what is needed for a ZeroConf host.


Similarly, maintenance and upgrade of routers can cause major disruptions to the network routing because the routing system and management of routers is not organized to minimize such disruption. Some improvements have been made, such as graceful restart mechanisms in protocols, but more needs to be done.


R(37) The routing system and routers should provide mechanisms that minimize the disruption to the network caused by maintenance and upgrades of software and hardware. This requirement recognizes that some of the capabilities needed are outside the scope of the routing architecture (e.g., minimum impact software upgrade).


3.6.6. Provability
3.6.6. 可证明性

R(38) The routing system and its component protocols must be demonstrated to be locally convergent under the permitted range of parameter settings and policy options that the operator(s) can select.


There are various methods for demonstration and proof that include, but are not limited to: mathematical proof, heuristic, and pattern recognition. No requirement is made on the method used for demonstrating local convergence properties.


R(39) Routing protocols employed by the routing system and the overall routing system should be resistant to bad routing policy decisions made by operators.


Tools are needed to check compatibility of routing policies. While these tools are not part of the routing architecture, the mechanisms to support such tools are.


Routing policies are compatible if their interaction does not cause instability. A domain or group of domains in a system is defined as being convergent, either locally or globally, if and only if, after an exchange of routing information, routing tables reach a stable state that does not change until the routing policies or the topology changes again.


To achieve the above-mentioned goals:


R(40) The routing system must provide a mechanism to publish and communicate policies so that operational coordination and fault isolation are possible.


Tools are required that verify the stability characteristics of the routing system in specified parts of the Internet. The tools should be efficient (fast) and have a broad scope of operation (check large portions of Internet). While these tools are not part of the architecture, developing them is in the interest of the architecture and should be defined as a Routing Research Group activity while research on the architecture is in progress.


Tools analyzing routing policies can be applied statically or (preferably) dynamically. A dynamic solution requires tools that can be used for run time checking for oscillations that arise from policy conflicts. Research is needed to find an efficient solution to the dynamic checking of oscillations.


3.6.7. Traffic Engineering
3.6.7. 交通工程

The ability to do traffic engineering and to get the feedback from the network to enable traffic engineering should be included in the future domain architecture. Though traffic engineering has many definitions, it is, at base, another alternative or extension for the path selection mechanisms of the routing system. No fundamental changes to the requirements are needed, but the iterative processes involved in traffic engineering may require some additional capabilities and state in the network.


Traffic engineering typically involves a combination of off-line network planning and administrative control functions in which the expected and measured traffic flows are examined, resulting in changes to static configurations and policies in the routing system.


During operations, these configurations control the actual flow of traffic and affect the dynamic path selection mechanisms; the results are measured and fed back into further rounds of network planning.

在操作期间,这些配置控制实际的交通流,并影响动态路径选择机制;测量结果并反馈到下一轮网络规划中。 Support for, and Provision of, Traffic Engineering Tools 支持和提供交通工程工具

At present, there is an almost total lack of effective traffic engineering tools, whether in real time for network control or off-line for network planning. The routing system should encourage the provision of such tools.


R(41) The routing system must generate statistical and accounting information in such a way that traffic engineering and network planning tools can be used in both real-time and off-line planning and management.

R(41)路由系统必须生成统计和会计信息,以便流量工程和网络规划工具可用于实时和离线规划和管理。 Support of Multiple Parallel Paths 支持多条并行路径

R(42) The routing system must support the controlled distribution over multiple links or paths of traffic toward the same destination. This applies to domains with two or more connections to the same neighbor domain, and to domains with connections to more than one neighbor domain. The paths need not have the same metric.


R(43) The routing system must support forwarding over multiple parallel paths when available. This support should extend to cases where the offered traffic is known to exceed the available capacity of a single link, and to the cases where load is to be shared over paths for cost or resiliency reasons.


R(44) Where traffic is forwarded over multiple parallel paths, the routing system must, so far as is possible, avoid the reordering of packets in individual micro-flows.


R(45) The routing system must have mechanisms to allow the traffic to be reallocated back onto a single path when multiple paths are not needed.

R(45)当不需要多条路径时,路由系统必须具有允许流量重新分配回单个路径的机制。 Peering Support 对等支持

R(46) The routing system must support peer-level connectivity as well as hierarchical connections between domains.


The network is becoming increasingly complex, with private peering arrangements set up between providers at every level of the hierarchy of service providers and even by certain large enterprises, in the form of dedicated extranets.


R(47) The routing system must facilitate traffic engineering of peer routes so that traffic can be readily constrained to travel as the network operators desire, allowing optimal use of the available connectivity.


3.6.8. Support for Middleboxes
3.6.8. 支持中间盒

One of our assumptions is that NATs and other middle-boxes such as firewalls, web proxies, and address family translators (e.g., IPv4 to IPv6) are here to stay.


R(48) The routing system should work in conjunction with middle-boxes, e.g., NAT, to aid in bi-directional connectivity without compromising the additional opacity and privacy that the middle-boxes offer.


This problem is closely analogous to the abstraction problem, which is already under discussion for the interchange of routing information between domains.


3.7. Performance Requirements
3.7. 性能要求

Over the past several years, the performance of the routing system has frequently been discussed. The requirements that derive from those discussions are listed below. The specific values for these performance requirements are left for further discussion.


R(49) The routing system must support domains of at least N systems. A system is taken to mean either an individual router or a domain.


R(50) Local convergence should occur within T units of time.


R(51) The routing system must be measurably reliable. The measure of reliability remains a research question.


R(52) The routing system must be locally stable to a measured degree. The degree of measurability remains a research issue.


R(53) The routing system must be globally stable to a measured degree. The degree of measurability remains a research issue.


R(54) The routing system should scale to an indefinitely large number of domains.


There has been very little data or statistical evidence for many of the performance claims made in the past. In recent years, several efforts have been initiated to gather data and do the analyses required to make scientific assessments of performance issues and requirements. In order to complete this section of the requirements analysis, the data and analyses from these studies needs to be gathered and collated into this document. This work has been started but has yet to be completed.


Editors' Note: This work was never completed due to corporate reorganizations.


3.8. Backward Compatibility (Cutover) and Maintainability
3.8. 向后兼容性(转换)和可维护性

This area poses a dilemma. On one hand, it is an absolute requirement that:


R(55) The introduction of the routing system must not require any flag days.


R(56) The network currently in place must continue to run at least as well as it does now while the new network is being installed around it.


However, at the same time, it is also an requirement that:


R(57) The new architecture must not be limited by the restrictions that plague today's network.


It has to be admitted that R(57) is not a well-defined requirement, because we have not fully articulated what the restrictions might be. Some of these restrictions can be derived by reading the discussions for the positive requirements above. It would be a useful exercise to explicitly list all the restrictions and irritations with which we wish to do away. Further, it would be useful to determine if these restrictions can currently be removed at a reasonable cost or whether we are actually condemned to live with them.


Those restrictions cannot be allowed to become permanent baggage on the new architecture. If they do, the effort to create a new system will come to naught. It may, however, be necessary to live with some of them temporarily for practical reasons while providing an architecture that will eventually allow them to be removed. The last three requirements have significance not only for the transition


strategy but also for the architecture itself. They imply that it must be possible for an internet such as today's BGP-controlled network, or one of its ASs, to exist as a domain within the new FDR.


3.9. Security Requirements
3.9. 安全要求

As previously discussed, one of the major changes that has overtaken the Internet since its inception is the erosion of trust between end users making use of the net, between those users and the suppliers of services, and between the multiplicity of providers. Hence, security, in all its aspects, will be much more important in the FDR.


It must be possible to secure the routing communication.


R(58) The communicating entities must be able to identify who sent and who received the information (authentication).


R(59) The communicating entities must be able to verify that the information has not been changed on the way (integrity).


Security is more important in inter-domain routing where the operator has no control over the other domains, than in intra-domain routing where all the links and the nodes are under the administration of the operator and can be expected to share a trust relationship. This property of intra-domain trust, however, should not be taken for granted:


R(60) Routing communications must be secured by default, but an operator must have the option to relax this requirement within a domain where analysis indicates that other means (such as physical security) provide an acceptable alternative.


R(61) The routing communication mechanism must be robust against denial-of-service attacks.


R(62) It should be possible to verify that the originator of the information was authorized to generate the information.


Further considerations that may impose further requirements include:


- whether no one else but the intended recipient is able to access (privacy) or understand (confidentiality) the information,

- 除预期接收人外,其他任何人是否能够访问(隐私)或理解(保密)信息,

- whether it is possible to verify that all the information has been received and that the two parties agree on what was sent (validation and non-repudiation),

- 是否有可能验证是否已收到所有信息,以及双方是否同意发送的信息(验证和不可否认),

- whether there is a need to separate security of routing from security of forwarding, and

- 是否需要将路由安全性与转发安全性分开,以及

- whether traffic flow security is needed (i.e., whether there is value in concealing who can connect to whom, and what volumes of data are exchanged).

- 是否需要交通流安全(即,隐藏谁可以连接谁以及交换的数据量是否有价值)。

Securing the BGP session, as done today, only secures the exchange of messages from the peering domain, not the content of the information. In other words, we can confirm that the information we got is what our neighbor really sent us, but we do not know whether or not this information (that originated in some remote domain) is true.


A decision has to be made on whether to rely on chains of trust (we trust our peers who trust their peers who..), or whether we also need authentication and integrity of the information end-to-end. This information includes both routes and addresses. There has been interest in having digital signatures on originated routes as well as countersignatures by address authorities to confirm that the originator has authority to advertise the prefix. Even understanding who can confirm the authority is non-trivial, as it might be the provider who delegated the prefix (with a whole chain of authority back to ICANN) or it may be an address registry. Where a prefix delegated by a provider is being advertised through another provider as in multi-homing, both may have to be involved to confirm that the prefix may be advertised through the provider who doesn't have any interest in the prefix!


R(63) The routing system must cooperate with the security policies of middle-boxes whenever possible.


This is likely to involve further requirements for abstraction of information. For example, a firewall that is seeking to minimize interchange of information that could lead to a security breach. The effect of such changes on the end-to-end principle should be carefully considered as discussed in [Blumenthal01].


R(64) The routing system must be capable of complying with local legal requirements for interception of communication.


3.10. Debatable Issues
3.10. 有争议的问题

This section covers issues that need to be considered and resolved in deciding on a Future Domain Routing architecture. While they can't be described as requirements, they do affect the types of solution that are acceptable. The discussions included below are very open-ended.


3.10.1. Network Modeling
3.10.1. 网络建模

The mathematical model that underlies today's routing system uses a graph representation of the network. Hosts, routers, and other processing boxes are represented by nodes and communications links by arcs. This is a topological model in that routing does not need to directly model the physical length of the links or the position of the nodes; the model can be transformed to provide a convenient picture of the network by adjusting the lengths of the arcs and the layout of the nodes. The connectivity is preserved and routing is unaffected by this transformation.


The routing algorithms in traditional routing protocols utilize a small number of results from graph theory. It is only recently that additional results have been employed to support constraint-based routing for traffic engineering.


The naturalness of this network model and the "fit" of the graph theoretical methods may have tended to blind us to alternative representations and inhibited us from seeking alternative strands of theoretical thinking that might provide improved results.


We should not allow this habitual behavior to stop us from looking for alternative representations and algorithms; topological revolutions are possible and allowed, at least in theory.


3.10.2. System Modeling
3.10.2. 系统建模

The assumption that object modeling of a system is an essential first step to creating a new system is still novel in this context. Frequently, the object modeling effort becomes an end in itself and does not lead to system creation. But there is a balance, and a lot that can be discovered in an ongoing effort to model a system such as the Future Domain Routing system. It is recommended that this process be included in the requirements. It should not, however, be a gating event to all other work.


Some of the most important realizations will occur during the process of determining the following:


- Object classification

- 对象分类

- Relationships and containment

- 关系与遏制

- Roles and Rules

- 角色和规则

3.10.3. One, Two, or Many Protocols
3.10.3. 一个、两个或多个协议

There has been a lot of discussion of whether the FDR protocol solution should consist of one (probably new) protocol, two (intra-and inter-domain) protocols, or many protocols. While it might be best to have one protocol that handles all situations, this seems improbable. On the other hand, maintaining the "strict" division evident in the network today between the IGP and EGP may be too restrictive an approach. Given this, and the fact that there are already many routing protocols in use, the only possible answer seems to be that the architecture should support many protocols. It remains an open issue, one for the solution, to determine if a new protocol needs to be designed in order to support the highest goals of this architecture. The expectation is that a new protocol will be needed.


3.10.4. Class of Protocol
3.10.4. 协议类别

If a new protocol is required to support the FDR architecture, the question remains open as to what kind of protocol this ought to be. It is our expectation that a map distribution protocol will be required to augment the current path-vector protocol and shortest path first protocols.


3.10.5. Map Abstraction
3.10.5. 地图抽象

Assuming that a map distribution protocol, as defined in [RFC1992] is required, what are the requirements on this protocol? If every detail is advertised throughout the Internet, there will be a lot of information. Scalable solutions require abstraction.


- If we summarize too much, some information will be lost on the way.

- 如果我们总结得太多,一些信息会在途中丢失。

- If we summarize too little, then more information than required is available, contributing to scaling limitations.

- 如果我们总结得太少,那么就可以获得比所需更多的信息,从而导致伸缩限制。

- One can allow more summarization, if there also is a mechanism to query for more details within policy limits.

- 如果还有一种在策略限制内查询更多详细信息的机制,则可以允许更多摘要。

- The basic requirement is not that the information shall be advertised, but rather that the information shall be available to those who need it. We should not presuppose a solution where advertising is the only possible mechanism.

- 基本要求不是要公布信息,而是向需要的人提供信息。我们不应该预设一个解决方案,即广告是唯一可能的机制。

3.10.6. Clear Identification for All Entities
3.10.6. 所有实体的清晰标识

As in all other fields, the words used to refer to concepts and to describe operations about routing are important. Rather than describe concepts using terms that are inaccurate or rarely used in the real world of networking, it is necessary to make an effort to use the correct words. Many networking terms are used casually, and the result is a partial or incorrect understanding of the underlying concept. Entities such as nodes, interfaces, subnetworks, tunnels, and the grouping concepts such as ASs, domains, areas, and regions, need to be clearly identified and defined to avoid confusion.


There is also a need to separate identifiers (what or who) from locators (where) from routes (how to reach).


Editors' Note: Work was undertaken in the shim6 working group of the IETF on this sort of separation. This work needs to be taken into account in any new routing architecture.


3.10.7. Robustness and Redundancy
3.10.7. 鲁棒性和冗余性

The routing association between two domains should survive even if some individual connection between two routers goes down.


The "session" should operate between logical "routing entities" on each domain side, and not necessarily be bound to individual routers or addresses. Such a logical entity can be physically distributed over multiple network elements. Or, it can reside in a single router, which would default to the current situation.


3.10.8. Hierarchy
3.10.8. 等级制度

A more flexible hierarchy with more levels and recursive groupings in both upward and downward directions allows more structured routing. The consequence is that no single level will get too big for routers to handle.


On the other hand, it appears that the real-world Internet is becoming less hierarchical, so that it will be increasingly difficult to use hierarchy to control scaling.


Note that groupings can look different depending on which aspect we use to define them. A Diffserv area, an MPLS domain, a trusted domain, a QoS area, a multicast domain, etc., do not always coincide; nor are they strict hierarchical subsets of each other. The basic distinction at each level is "this grouping versus everything outside".


3.10.9. Control Theory
3.10.9. 控制理论

Is it possible to apply a control theory framework to analyze the stability of the control system of the whole network domain, with regard to, e.g., convergence speed and the frequency response, and then use the results from that analysis to set the timers and other protocol parameters?


Control theory could also play a part in QoS routing, by modifying current link-state protocols with link costs dependent on load and feedback. Control theory is often used to increase the stability of dynamic systems.


It might be possible to construct a new, totally dynamic routing protocol solely on a control theoretic basis, as opposed to the current protocols that are based in graph theory and static in nature.


3.10.10. Byzantium
3.10.10. 拜占庭

Is solving the Byzantine Generals problem a requirement? This is the problem of reaching a consensus among distributed units if some of them give misleading answers. The current intra-domain routing system is, at one level, totally intolerant of misleading information. However, the effect of different sorts of misleading or incorrect information has vastly varying results, from total collapse to purely local disconnection of a single domain. This sort of behavior is not very desirable.


There are, possibly, other network robustness issues that must be researched and resolved.


3.10.11. VPN Support
3.10.11. VPN支持

Today, BGP is also used for VPNs, for example, as described in RFC 4364 [RFC4364].

今天,BGP也用于VPN,例如,如RFC 4364[RFC4364]中所述。

Internet routing and VPN routing have different purposes and most often exchange different information between different devices. Most Internet routers do not need to know VPN-specific information. The concepts should be clearly separated.


But when it comes to the mechanisms, VPN routing can share the same protocol as ordinary Internet routing; it can use a separate instance of the same protocol or it can use a different protocol. All variants are possible and have their own merits. These requirements are silent on this issue.


3.10.12. End-to-End Reliability
3.10.12. 端到端可靠性

The existing Internet architecture neither requires nor provides end-to-end reliability of control information dissemination. There is, however, already a requirement for end-to-end reliability of control information distribution, i.e., the ends of the VPN established need to have an acknowledgment of the success in setting up the VPN. While it is not necessarily the function of a routing architecture to provide end-to-end reliability for this kind of purpose, we must be clear that end-to-end reliability becomes a requirement if the network has to support such reliable control signaling. There may be other requirements that derive from requiring the FDR to support reliable control signaling.


3.10.13. End-to-End Transparency
3.10.13. 端到端透明度

The introduction of private addressing schemes, Network Address Translators, and firewalls has significantly reduced the end-to-end transparency of the network. In many cases, the network is also no longer symmetric, so that communication between two addresses is possible if the communication session originates from one end but not from the other. This impedes the deployment of new peer-to-peer services and some "push" services where the server in a client-server arrangement originates the communication session. Whether a new routing system either can or should seek to restore this transparency is an open issue.


A related issue is the extent to which end-user applications should seek to control the routing of communications to the rest of the network.


4. Security Considerations
4. 安全考虑

We address security issues in the individual requirements. We do require that the architecture and protocols developed against this set of requirements be "secure". Discussion of specific security issues can be found in the following sections:


o Group A: Routing System Security - Section 2.1.9

o A组:路由系统安全-第2.1.9节

o Group A: End Host Security - Section 2.1.10

o A组:终端主机安全-第2.1.10节

o Group A: Routing Information Policies - Section

o A组:路由信息策略-第2.1.11.1节

o Group A: Abstraction - Section 2.1.16

o A组:抽象-第2.1.16节

o Group A: Robustness - Section 2.1.18

o A组:稳健性-第2.1.18节

o Group B: Protection against Denial-of-Service and Other Security Attacks - Section

o B组:针对拒绝服务和其他安全攻击的保护-第3.2.3.8节

o Group B: Commercial Service Providers - Section

o B组:商业服务提供商-第3.3.1.1节

o Group B: The Federated Environment - Section 3.4.1

o B组:联邦环境-第3.4.1节

o Group B: Path Advertisement - Section

o B组:路径广告-第3.6.2.2节

o Group B: Security Requirements - Section 3.9

o B组:安全要求-第3.9节

5. IANA Considerations
5. IANA考虑

This document is a set of requirements from which a new routing and addressing architecture may be developed. From that architecture, a new protocol, or set of protocols, may be developed.


While this note poses no new tasks for IANA, the architecture and protocols developed from this document probably will have issues to be dealt with by IANA.


6. Acknowledgments
6. 致谢

This document is the combined effort of two groups in the IRTF. Group A, which was formed by the IRTF Routing Research chairs, and Group B, which was self-formed and later was folded into the IRTF Routing Research Group. Each group has it own set of acknowledgments.


Group A Acknowledgments


This originated in the IRTF Routing Research Group's sub-group on Inter-domain routing requirements. The members of the group were:


Abha Ahuja Danny McPherson J. Noel Chiappa David Meyer Sean Doran Mike O'Dell JJ Garcia-Luna-Aceves Andrew Partan Susan Hares Radia Perlman Geoff Huston Yakov Rehkter Frank Kastenholz John Scudder Dave Katz Curtis Villamizar Tony Li Dave Ward


We also appreciate the comments and review received from Ran Atkinson, Howard Berkowitz, Randy Bush, Avri Doria, Jeffery Haas, Dmitri Krioukov, Russ White, and Alex Zinin. Special thanks to Yakov Rehkter for contributing text and to Noel Chiappa.

我们还感谢Ran Atkinson、Howard Berkowitz、Randy Bush、Avri Doria、Jeffery Haas、Dmitri Krioukov、Russ White和Alex Zinin的评论和评论。特别感谢亚科夫·雷克特对本文的贡献和诺埃尔·基亚帕。

Group B Acknowledgments


The document is derived from work originally produced by Babylon. Babylon was a loose association of individuals from academia, service providers, and vendors whose goal was to discuss issues in Internet routing with the intention of finding solutions for those problems.


The individual members who contributed materially to this document are: Anders Bergsten, Howard Berkowitz, Malin Carlzon, Lenka Carr Motyckova, Elwyn Davies, Avri Doria, Pierre Fransson, Yong Jiang, Dmitri Krioukov, Tove Madsen, Olle Pers, and Olov Schelen.


Thanks also go to the members of Babylon and others who did substantial reviews of this material. Specifically, we would like to acknowledge the helpful comments and suggestions of the following individuals: Loa Andersson, Tomas Ahlstrom, Erik Aman, Thomas Eriksson, Niklas Borg, Nigel Bragg, Thomas Chmara, Krister Edlund, Owe Grafford, Torbjorn Lundberg, Jeremy Mineweaser, Jasminko Mulahusic, Florian-Daniel Otel, Bernhard Stockman, Tom Worster, and Roberto Zamparo.


In addition, the authors are indebted to the folks who wrote all the references we have consulted in putting this paper together. This includes not only the references explicitly listed below, but also those who contributed to the mailing lists we have been participating in for years.


The editors thank Lixia Zhang, as IRSG document shepherd, for her help and her perseverance, without which this document would never have been published.


Finally, it is the editors who are responsible for any lack of clarity, any errors, glaring omissions or misunderstandings.


7. Informative References
7. 资料性引用

[Blumenthal01] Blumenthal, M. and D. Clark, "Rethinking the design of the Internet: The end to end arguments vs. the brave new world", May 2001, <>.


[Broido02] Broido, A., Nemeth, E., Claffy, K., and C. Elves, "Internet Expansion, Refinement and Churn", February 2002.


[CIDR] Telcordia Technologies, "CIDR Report", <>.

[CIDR]Telcordia Technologies,“CIDR报告”<>.

[Chiappa02] Chiappa, N., "A New IP Routing and Addressing Architecture", July 1991, <>.


[Clark91] Clark, D., "Quote reportedly from IETF Plenary discussion", 1991.


[DiffservAR] Seddigh, N., Nandy, B., and J. Heinanen, "An Assured Rate Per-Domain Behaviour for Differentiated Services", Work in Progress, July 2001.


[DiffservVW] Jacobson, V., Nichols, K., and K. Poduri, "The 'Virtual Wire' Per-Domain Behavior", Work in Progress, July 2000.


[Griffin99] Griffin, T. and G. Wilfong, "An Analysis of BGP Convergence Properties", SIGCOMM 1999.

[Griffin 99]Griffin,T.和G.Wilfong,“BGP收敛性分析”,SIGCOMM 1999。

[ISO10747] ISO/IEC, "Protocol for Exchange of Inter-Domain Routeing Information among Intermediate Systems to Support Forwarding of ISO 8473 PDUs", International Standard 10747 ISO/IEC JTC 1, Switzerland, 1993.

[ISO10747]ISO/IEC,“支持ISO 8473 PDU转发的中间系统间域间路由信息交换协议”,国际标准10747 ISO/IEC JTC 1,瑞士,1993年。

[InferenceSRLG] Papadimitriou, D., Poppe, F., J. Jones, J., S. Venkatachalam, S., S. Dharanikota, S., Jain, R., Hartani, R., and D. Griffith, "Inference of Shared Risk Link Groups", Work in Progress, November 2001.


[ODell01] O'Dell, M., "Private Communication", 2001.


[RFC1126] Little, M., "Goals and functional requirements for inter-autonomous system routing", RFC 1126, October 1989.


[RFC1726] Partridge, C. and F. Kastenholz, "Technical Criteria for Choosing IP The Next Generation (IPng)", RFC 1726, Dec 1994.

[RFC1726]Partridge,C.和F.Kastenholz,“选择下一代IP的技术标准(IPng)”,RFC 17261994年12月。

[RFC1992] Castineyra, I., Chiappa, N., and M. Steenstrup, "The Nimrod Routing Architecture", RFC 1992, August 1996.

[RFC1992]Castineyra,I.,Chiapa,N.,和M.Steenstrup,“Nimrod路由架构”,RFC 1992,1996年8月。

[RFC2071] Ferguson, P. and H. Berkowitz, "Network Renumbering Overview: Why would I want it and what is it anyway?", RFC 2071, January 1997.

[RFC2071]Ferguson,P.和H.Berkowitz,“网络重新编号概述:我为什么想要它以及它到底是什么?”,RFC 2071,1997年1月。

[RFC2072] Berkowitz, H., "Router Renumbering Guide", RFC 2072, January 1997.

[RFC2072]Berkowitz,H.,“路由器重新编号指南”,RFC 2072,1997年1月。

[RFC3031] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol Label Switching Architecture", RFC 3031, January 2001.

[RFC3031]Rosen,E.,Viswanathan,A.,和R.Callon,“多协议标签交换体系结构”,RFC 30312001年1月。

[RFC3221] Huston, G., "Commentary on Inter-Domain Routing in the Internet", RFC 3221, December 2001.


[RFC3260] Grossman, D., "New Terminology and Clarifications for Diffserv", RFC 3260, April 2002.

[RFC3260]Grossman,D.“区分服务的新术语和澄清”,RFC 3260,2002年4月。

[RFC3344] Perkins, C., "IP Mobility Support.", RFC 3344, August 2002.


[RFC3345] McPherson, D., Gill, V., Walton, D., and A. Retana, "Border Gateway Protocol (BGP) Persistent Route Oscillation Condition", RFC 3345, August 2002.

[RFC3345]McPherson,D.,Gill,V.,Walton,D.,和A.Retana,“边界网关协议(BGP)持续路由振荡条件”,RFC 33452002年8月。

[RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description", RFC 3471, January 2003.

[RFC3471]Berger,L.“通用多协议标签交换(GMPLS)信令功能描述”,RFC 3471,2003年1月。

[RFC3963] Devarapalli, V., Wakikawa, R., Petrescu, A., and P. Thubert, "Network Mobility (NEMO) Basic Support Protocol", RFC 3963, January 2005.

[RFC3963]Devarapalli,V.,Wakikawa,R.,Petrescu,A.,和P.Thubert,“网络移动(NEMO)基本支持协议”,RFC 3963,2005年1月。

[RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private Networks (VPNs)", RFC 4364, February 2006.

[RFC4364]Rosen,E.和Y.Rekhter,“BGP/MPLS IP虚拟专用网络(VPN)”,RFC 4364,2006年2月。

[RFC5773] Davies, E. and A. Doria, "Analysis of Inter-Domain Routing Requirements and History", RFC 5773, February 2010.

[RFC5773]Davies,E.和A.Doria,“域间路由需求和历史分析”,RFC 5773,2010年2月。

[Wroclawski95] Wroclowski, J., "The Metanet White Paper - Workshop on Research Directions for the Next Generation Internet", 1995.


[netconf-charter] Internet Engineering Task Force, "IETF Network Configuration working group", 2005, <>.


[policy-charter02] Internet Engineering Task Force, "IETF Policy working group", 2002, < policy-charter.html>.

[policy-charter02]互联网工程任务组,“IETF政策工作组”,2002年< policycharter.html>。

[rap-charter02] Internet Engineering Task Force, "IETF Resource Allocation Protocol working group", 2002, <>.


[snmpconf-charter02] Internet Engineering Task Force, "IETF Configuration management with SNMP working group", 2002, <http://>.

[snmpconf-charter02]互联网工程任务组,“IETF配置管理与SNMP工作组”,2002年,< charter.html>。

Authors' Addresses


Avri Doria LTU Lulea 971 87 Sweden

Avri Doria LTU Lulea 971 87瑞典

   Phone: +46 73 277 1788
   Phone: +46 73 277 1788

Elwyn B. Davies Folly Consulting Soham, Cambs UK

Elwyn B.Davies Folly Consulting Soham,英国剑桥

   Phone: +44 7889 488 335
   Phone: +44 7889 488 335

Frank Kastenholz BBN Technologies 10 Moulton St. Cambridge, MA 02183 USA

Frank Kastenholz BBN Technologies美国马萨诸塞州剑桥莫尔顿街10号,邮编02183

   Phone: +1 617 873 8047
   Phone: +1 617 873 8047