Internet Engineering Task Force (IETF) L. Fang, Ed.
Request for Comments: 6965 Cisco
Category: Informational N. Bitar
ISSN: 2070-1721 Verizon
R. Zhang
Alcatel-Lucent
M. Daikoku
KDDI
P. Pan
Infinera
August 2013
Internet Engineering Task Force (IETF) L. Fang, Ed.
Request for Comments: 6965 Cisco
Category: Informational N. Bitar
ISSN: 2070-1721 Verizon
R. Zhang
Alcatel-Lucent
M. Daikoku
KDDI
P. Pan
Infinera
August 2013
MPLS Transport Profile (MPLS-TP) Applicability: Use Cases and Design
MPLS传输配置文件（MPLS-TP）适用性：用例和设计
Abstract
摘要
This document describes the applicability of the MPLS Transport Profile (MPLS-TP) with use case studies and network design considerations. The use cases include Metro Ethernet access and aggregation transport, mobile backhaul, and packet optical transport.
本文档描述了MPLS传输配置文件（MPLS-TP）的适用性，以及用例研究和网络设计考虑事项。用例包括城域以太网接入和聚合传输、移动回程和分组光传输。
Status of This Memo
关于下段备忘
This document is not an Internet Standards Track specification; it is published for informational purposes.
本文件不是互联网标准跟踪规范；它是为了提供信息而发布的。
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Not all documents approved by the IESG are a candidate for any level of Internet Standard; see Section 2 of RFC 5741.
本文件是互联网工程任务组（IETF）的产品。它代表了IETF社区的共识。它已经接受了公众审查，并已被互联网工程指导小组（IESG）批准出版。并非IESG批准的所有文件都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 http://www.rfc-editor.org/info/rfc6965.
有关本文件当前状态、任何勘误表以及如何提供反馈的信息，请访问http://www.rfc-editor.org/info/rfc6965.
Copyright Notice
版权公告
Copyright (c) 2013 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2013 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 (http://trustee.ietf.org/license-info) 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. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
本文件受BCP 78和IETF信托有关IETF文件的法律规定的约束(http://trustee.ietf.org/license-info)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。从本文件中提取的代码组件必须包括信托法律条款第4.e节中所述的简化BSD许可证文本，并提供简化BSD许可证中所述的无担保。
Table of Contents
目录
1. Introduction ....................................................3
1.1. Terminology ................................................3
1.2. Background .................................................4
2. MPLS-TP Use Cases ...............................................6
2.1. Metro Access and Aggregation ...............................6
2.2. Packet Optical Transport ...................................7
2.3. Mobile Backhaul ............................................8
2.3.1. 2G and 3G Mobile Backhaul ...........................8
2.3.2. 4G/LTE Mobile Backhaul ..............................9
3. Network Design Considerations ..................................10
3.1. The Role of MPLS-TP .......................................10
3.2. Provisioning Mode .........................................10
3.3. Standards Compliance ......................................10
3.4. End-to-End MPLS OAM Consistency ...........................11
3.5. PW Design Considerations in MPLS-TP Networks ..............11
3.6. Proactive and On-Demand MPLS-TP OAM Tools .................12
3.7. MPLS-TP and IP/MPLS Interworking Considerations ...........12
4. Security Considerations ........................................13
5. Acknowledgements ...............................................13
6. References .....................................................13
6.1. Normative References ......................................13
6.2. Informative References ....................................14
7. Contributors ...................................................15
1. Introduction ....................................................3
1.1. Terminology ................................................3
1.2. Background .................................................4
2. MPLS-TP Use Cases ...............................................6
2.1. Metro Access and Aggregation ...............................6
2.2. Packet Optical Transport ...................................7
2.3. Mobile Backhaul ............................................8
2.3.1. 2G and 3G Mobile Backhaul ...........................8
2.3.2. 4G/LTE Mobile Backhaul ..............................9
3. Network Design Considerations ..................................10
3.1. The Role of MPLS-TP .......................................10
3.2. Provisioning Mode .........................................10
3.3. Standards Compliance ......................................10
3.4. End-to-End MPLS OAM Consistency ...........................11
3.5. PW Design Considerations in MPLS-TP Networks ..............11
3.6. Proactive and On-Demand MPLS-TP OAM Tools .................12
3.7. MPLS-TP and IP/MPLS Interworking Considerations ...........12
4. Security Considerations ........................................13
5. Acknowledgements ...............................................13
6. References .....................................................13
6.1. Normative References ......................................13
6.2. Informative References ....................................14
7. Contributors ...................................................15
This document describes the applicability of the MPLS Transport Profile (MPLS-TP) with use case studies and network design considerations.
本文档描述了MPLS传输配置文件（MPLS-TP）的适用性，以及用例研究和网络设计考虑事项。
Term Definition
------ -------------------------------------------------------
2G 2nd generation of mobile telecommunications technology
3G 3rd generation of mobile telecommunications technology
4G 4th generation of mobile telecommunications technology
ADSL Asymmetric Digital Subscriber Line
AIS Alarm Indication Signal
ATM Asynchronous Transfer Mode
BFD Bidirectional Forwarding Detection
BTS Base Transceiver Station
CC-V Continuity Check and Connectivity Verification
CDMA Code Division Multiple Access
E-LINE Ethernet line; provides point-to-point connectivity
E-LAN Ethernet LAN; provides multipoint connectivity
eNB Evolved Node B
EPC Evolved Packet Core
E-VLAN Ethernet Virtual Private LAN
EVDO Evolution-Data Optimized
G-ACh Generic Associated Channel
GAL G-ACh Label
GMPLS Generalized Multiprotocol Label Switching
GSM Global System for Mobile Communications
HSPA High Speed Packet Access
IPTV Internet Protocol television
L2VPN Layer 2 Virtual Private Network
L3VPN Layer 3 Virtual Private Network
LAN Local Access Network
LDI Link Down Indication
LDP Label Distribution Protocol
LSP Label Switched Path
LTE Long Term Evolution
MEP Maintenance Entity Group End Point
MIP Maintenance Entity Group Intermediate Point
MPLS Multiprotocol Label Switching
MPLS-TP MPLS Transport Profile
MS-PW Multi-Segment Pseudowire
NMS Network Management System
OAM Operations, Administration, and Maintenance
PE Provider-Edge device
PW Pseudowire
Term Definition
------ -------------------------------------------------------
2G 2nd generation of mobile telecommunications technology
3G 3rd generation of mobile telecommunications technology
4G 4th generation of mobile telecommunications technology
ADSL Asymmetric Digital Subscriber Line
AIS Alarm Indication Signal
ATM Asynchronous Transfer Mode
BFD Bidirectional Forwarding Detection
BTS Base Transceiver Station
CC-V Continuity Check and Connectivity Verification
CDMA Code Division Multiple Access
E-LINE Ethernet line; provides point-to-point connectivity
E-LAN Ethernet LAN; provides multipoint connectivity
eNB Evolved Node B
EPC Evolved Packet Core
E-VLAN Ethernet Virtual Private LAN
EVDO Evolution-Data Optimized
G-ACh Generic Associated Channel
GAL G-ACh Label
GMPLS Generalized Multiprotocol Label Switching
GSM Global System for Mobile Communications
HSPA High Speed Packet Access
IPTV Internet Protocol television
L2VPN Layer 2 Virtual Private Network
L3VPN Layer 3 Virtual Private Network
LAN Local Access Network
LDI Link Down Indication
LDP Label Distribution Protocol
LSP Label Switched Path
LTE Long Term Evolution
MEP Maintenance Entity Group End Point
MIP Maintenance Entity Group Intermediate Point
MPLS Multiprotocol Label Switching
MPLS-TP MPLS Transport Profile
MS-PW Multi-Segment Pseudowire
NMS Network Management System
OAM Operations, Administration, and Maintenance
PE Provider-Edge device
PW Pseudowire
RAN Radio Access Network RDI Remote Defect Indication S-PE PW Switching Provider Edge S1 LTE Standardized interface between eNB and EPC SDH Synchronous Digital Hierarchy SONET Synchronous Optical Network SP Service Provider SRLG Shared Risk Link Groups SS-PW Single-Segment Pseudowire TDM Time-Division Multiplexing TFS Time and Frequency Synchronization tLDP Targeted Label Distribution Protocol UMTS Universal Mobile Telecommunications System VPN Virtual Private Network X2 LTE Standardized interface between eNBs for handover
RAN无线接入网RDI远程缺陷指示S-PE PW交换提供商Edge S1 LTE eNB和EPC SDH之间的标准化接口同步数字体系SONET同步光网络SP服务提供商SRLG共享风险链路组SS-PW单段伪线TDM时分复用TFS时间和频率同步tLDP目标标签分发协议UMTS通用移动通信系统VPN虚拟专用网X2用于切换的ENB之间的LTE标准化接口
Traditional transport technologies include SONET/SDH, TDM, and ATM. There is a transition away from these transport technologies to new packet transport technologies. In addition to the increasing demand for bandwidth, packet transport technologies offer the following key advantages:
传统的传输技术包括SONET/SDH、TDM和ATM。从这些传输技术向新的分组传输技术过渡。除了不断增长的带宽需求外，分组传输技术还具有以下关键优势：
Bandwidth efficiency:
带宽效率：
Traditional TDM transport technologies support fixed bandwidth with no statistical multiplexing. The bandwidth is reserved in the transport network, regardless of whether or not it is used by the client. In contrast, packet technologies support statistical multiplexing. This is the most important motivation for the transition from traditional transport technologies to packet transport technologies. The proliferation of new distributed applications that communicate with servers over the network in a bursty fashion has been driving the adoption of packet transport techniques, since packet multiplexing of traffic from bursty sources provides more efficient use of bandwidth than traditional circuit-based TDM technologies.
传统的TDM传输技术支持固定带宽，无需统计复用。无论客户端是否使用带宽，带宽都保留在传输网络中。相反，分组技术支持统计复用。这是从传统传输技术向分组传输技术过渡的最重要动机。以突发方式通过网络与服务器通信的新分布式应用程序的激增推动了分组传输技术的采用，因为来自突发源的流量的分组复用比传统的基于电路的TDM技术提供了更有效的带宽利用。
Flexible data rate connections:
灵活的数据速率连接：
The granularity of data rate connections of traditional transport technologies is limited to the rigid Plesiochronous Digital Hierarchy (PDH) hierarchy (e.g., DS1, DS3) or SONET hierarchy (e.g., OC3, OC12). Packet technologies support flexible data rate connections. The support of finer data rate granularity is particularly important for today's wireline and wireless services and applications.
传统传输技术的数据速率连接的粒度限于刚性准同步数字体系（PDH）体系（例如DS1、DS3）或SONET体系（例如OC3、OC12）。分组技术支持灵活的数据速率连接。支持更精细的数据速率粒度对于当今的有线和无线服务和应用程序尤为重要。
QoS support:
QoS支持：
Traditional transport technologies (such as TDM) provide bandwidth guarantees, but they are unaware of the types of traffic they carry. They are not packet aware and do not provide packet-level services. Packet transport can provide the differentiated services capability needed to support oversubscription and to deal with traffic prioritization upon congestion: issues that arise only in packet networks.
传统传输技术（如TDM）提供带宽保证，但它们不知道所承载的流量类型。它们不知道数据包，不提供数据包级别的服务。分组传输可以提供所需的差异化服务能力，以支持超额订阅和处理拥塞时的流量优先级：这些问题仅出现在分组网络中。
The root cause for transport moving to packet transport is the shift of applications from TDM to packet -- for example, Voice TDM to VoIP, Video to Video over IP, TDM access lines to Ethernet, and TDM VPNs to IP VPNs and Ethernet VPNs. In addition, network convergence and technology refreshes contribute to the demand for a common and flexible infrastructure that provides multiple services.
传输转移到数据包传输的根本原因是应用程序从TDM转移到数据包——例如，语音TDM到VoIP，视频到IP视频，TDM接入线到以太网，TDM VPN到IP VPN和以太网VPN。此外，网络融合和技术更新促进了对提供多种服务的通用灵活基础设施的需求。
As part of the MPLS family, MPLS-TP complements existing IP/MPLS technologies; it closes the gaps in the traditional access and aggregation transport to enable end-to-end packet technology solutions in a cost efficient, reliable, and interoperable manner. After several years of industry debate on which packet technology to use, MPLS-TP has emerged as the next generation transport technology of choice for many Service Providers worldwide.
作为MPLS系列的一部分，MPLS-TP补充了现有的IP/MPLS技术；它填补了传统访问和聚合传输的空白，以经济高效、可靠和互操作的方式实现端到端数据包技术解决方案。经过几年业界关于使用哪种分组技术的争论，MPLS-TP已经成为全球许多服务提供商选择的下一代传输技术。
The Unified MPLS strategy -- using MPLS from core to aggregation and access (e.g., IP/MPLS in the core, IP/MPLS or MPLS-TP in aggregation and access) -- appears to be very attractive to many SPs. It streamlines the operation, reduces the overall complexity, and improves end-to-end convergence. It leverages the MPLS experience and enhances the ability to support revenue-generating services.
统一的MPLS战略——从核心到聚合和访问使用MPLS（例如，在核心中使用IP/MPLS，在聚合和访问中使用IP/MPLS或MPLS-TP）——似乎对许多SP非常有吸引力。它简化了操作，降低了总体复杂性，并改进了端到端的收敛性。它利用了MPLS体验，增强了支持创收服务的能力。
MPLS-TP is a subset of MPLS functions that meet the packet transport requirements defined in [RFC5654]. This subset includes: MPLS data forwarding, pseudowire encapsulation for circuit emulation, and dynamic control plane using GMPLS control for LSP and tLDP for pseudowire (PW). MPLS-TP also extends previous MPLS OAM functions, such as the BFD extension for proactive Connectivity Check and Connectivity Verification (CC-V) [RFC6428], Remote Defect Indication (RDI) [RFC6428], and LSP Ping Extension for on-demand CC-V [RFC6426]. New tools have been defined for alarm suppression with Alarm Indication Signal (AIS) [RFC6427] and switch-over triggering with Link Down Indication (LDI) [RFC6427]. Note that since the MPLS OAM feature extensions defined through the process of MPLS-TP development are part of the MPLS family, the applicability is general to MPLS and not limited to MPLS-TP.
MPLS-TP是满足[RFC5654]中定义的数据包传输要求的MPLS功能的子集。该子集包括：MPLS数据转发、用于电路仿真的伪线封装，以及使用GMPLS控制的LSP和用于伪线（PW）的tLDP的动态控制平面。MPLS-TP还扩展了以前的MPLS OAM功能，例如用于主动连接检查和连接验证（CC-V）[RFC6428]的BFD扩展、远程缺陷指示（RDI）[RFC6428]和用于按需CC-V[RFC6426]的LSP Ping扩展。定义了新的工具，用于使用报警指示信号（AIS）[RFC6427]抑制报警，以及使用链路下降指示（LDI）[RFC6427]触发切换。请注意，由于通过MPLS-TP开发过程定义的MPLS OAM功能扩展是MPLS系列的一部分，因此适用于MPLS，而不限于MPLS-TP。
The requirements of MPLS-TP are provided in the MPLS-TP requirements document [RFC5654], and the architectural framework is defined in the MPLS-TP framework document [RFC5921]. This document's intent is to provide the use case studies and design considerations from a practical point of view based on Service Providers' deployments plans as well as actual deployments.
MPLS-TP的要求在MPLS-TP要求文件[RFC5654]中提供，架构框架在MPLS-TP框架文件[RFC5921]中定义。本文档旨在根据服务提供商的部署计划和实际部署，从实用角度提供用例研究和设计考虑。
The most common use cases for MPLS-TP include Metro access and aggregation, mobile backhaul, and packet optical transport. MPLS-TP data-plane architecture, path protection mechanisms, and OAM functionality are used to support these deployment scenarios.
MPLS-TP最常见的用例包括城域接入和聚合、移动回程和分组光传输。MPLS-TP数据平面体系结构、路径保护机制和OAM功能用于支持这些部署场景。
The design considerations discussed in this document include the role of MPLS-TP in the network, provisioning options, standards compliance, end-to-end forwarding and OAM consistency, compatibility with existing IP/MPLS networks, and optimization vs. simplicity design trade-offs.
本文档中讨论的设计考虑因素包括MPLS-TP在网络中的作用、供应选项、标准遵从性、端到端转发和OAM一致性、与现有IP/MPLS网络的兼容性，以及优化与简单设计之间的权衡。
The use of MPLS-TP for Metro access and aggregation transport is the most common deployment scenario observed in the field.
使用MPLS-TP进行城域接入和聚合传输是现场观察到的最常见部署场景。
Some operators are building green-field access and aggregation transport infrastructure, while others are upgrading or replacing their existing transport infrastructure with new packet technologies. The existing legacy access and aggregation networks are usually based on TDM or ATM technologies. Some operators are replacing these networks with MPLS-TP technologies, since legacy ATM/TDM aggregation and access are becoming inadequate to support the rapid business growth and too expensive to maintain. In addition, in many cases the legacy devices are facing End of Sale and End of Life issues. As operators must move forward with the next-generation packet technology, the adoption of MPLS-TP in access and aggregation becomes a natural choice. The statistical multiplexing in MPLS-TP helps to achieve higher efficiency compared with the time-division scheme in the legacy technologies. MPLS-TP OAM tools and protection mechanisms help to maintain high reliability of transport networks and achieve fast recovery.
一些运营商正在建设绿地接入和聚合传输基础设施，而另一些运营商正在用新的分组技术升级或替换现有的传输基础设施。现有的传统接入和聚合网络通常基于TDM或ATM技术。一些运营商正在用MPLS-TP技术取代这些网络，因为传统的ATM/TDM聚合和访问已不足以支持业务的快速增长，而且维护成本太高。此外，在许多情况下，传统设备都面临着销售结束和寿命终止问题。由于运营商必须推进下一代分组技术，在接入和聚合中采用MPLS-TP成为一种自然选择。与传统技术中的时分复用方案相比，MPLS-TP中的统计复用有助于实现更高的效率。MPLS-TP OAM工具和保护机制有助于保持传输网络的高可靠性并实现快速恢复。
As most Service Providers' core networks are MPLS enabled, extending the MPLS technology to the aggregation and access transport networks with a Unified MPLS strategy is very attractive to many Service Providers. Unified MPLS strategy in this document means having end-to-end MPLS technologies through core, aggregation, and access. It reduces operating expenses by streamlining the operation and
由于大多数服务提供商的核心网络都支持MPLS，因此使用统一的MPLS策略将MPLS技术扩展到聚合和访问传输网络对许多服务提供商来说非常有吸引力。本文档中的统一MPLS战略意味着通过核心、聚合和访问实现端到端MPLS技术。它通过简化运营和管理来减少运营费用
leveraging the operational experience already gained with MPLS technologies; it also improves network efficiency and reduces end-to-end convergence time.
利用MPLS技术已经获得的运营经验；它还提高了网络效率，减少了端到端的收敛时间。
The requirements from the SPs for ATM/TDM aggregation replacement often include:
SP对ATM/TDM聚合替换的要求通常包括：
- maintaining the previous operational model, which means providing a similar user experience in NMS,
- 保持以前的运营模式，这意味着在NMS中提供类似的用户体验，
- supporting the existing access network (e.g., Ethernet, ADSL, ATM, TDM, etc.) and connections with the core networks, and
- 支持现有接入网络（如以太网、ADSL、ATM、TDM等）和与核心网络的连接，以及
- supporting the same operational capabilities and services (L3VPN, L2VPN, E-LINE/E-LAN/E-VLAN, Dedicated Line, etc.).
- 支持相同的操作能力和服务（L3VPN、L2VPN、E-LINE/E-LAN/E-VLAN、专线等）。
MPLS-TP can meet these requirements and, in general, the requirements defined in [RFC5654] to support a smooth transition.
MPLS-TP可以满足这些要求，并且通常可以满足[RFC5654]中定义的要求，以支持平稳过渡。
Many SPs' transport networks consist of both packet and optical portions. The transport operators are typically sensitive to network deployment cost and operational simplicity. MPLS-TP supports both static provisioning through NMS and dynamic provisioning via the GMPLS control plane. As such, it is viewed as a natural fit in transport networks where the operators can utilize the MPLS-TP LSPs (including the ones statically provisioned) to manage user traffic as "circuits" in both packet and optical networks. Also, when the operators are ready, they can migrate the network to use the dynamic control plane for greater efficiency.
许多SP的传输网络由分组和光部分组成。传输运营商通常对网络部署成本和操作简单性非常敏感。MPLS-TP支持通过NMS的静态资源调配和通过GMPLS控制平面的动态资源调配。因此，它被视为在传输网络中的自然适合，其中运营商可以利用MPLS-TP lsp（包括静态供应的lsp）在分组和光网络中作为“电路”来管理用户业务。此外，当运营商准备就绪时，他们可以迁移网络以使用动态控制平面以提高效率。
Among other attributes, bandwidth management, protection/recovery, and OAM are critical in packet/optical transport networks. In the context of MPLS-TP, LSPs may be associated with bandwidth allocation policies. OAM is to be performed on each individual LSP. For some of the performance monitoring functions, the OAM mechanisms need to be able to transmit and process OAM packets at very high frequency. An overview of the MPLS-TP OAM toolset is found in [RFC6669].
在其他属性中，带宽管理、保护/恢复和OAM在分组/光传输网络中至关重要。在MPLS-TP的上下文中，lsp可与带宽分配策略相关联。对每个LSP执行OAM。对于某些性能监视功能，OAM机制需要能够以非常高的频率传输和处理OAM数据包。在[RFC6669]中可以找到MPLS-TP OAM工具集的概述。
Protection, as defined in [RFC6372], is another important element in transport networks. Typically, ring and linear protection can be readily applied in metro networks. However, as long-haul networks are sensitive to bandwidth cost and tend to have mesh-like topology, shared mesh protection is becoming increasingly important.
[RFC6372]中定义的保护是传输网络中的另一个重要元素。通常，环形和线性保护可以很容易地应用于城域网。然而，由于长途网络对带宽成本非常敏感，并且往往具有网状拓扑结构，因此共享网状保护变得越来越重要。
In some cases, SPs plan to deploy MPLS-TP from their long-haul optical packet transport all the way to the aggregation and access in their networks.
在某些情况下，SP计划部署MPLS-TP，从其长途光分组传输一直到其网络中的聚合和访问。
Wireless communication is one of the fastest growing areas in communication worldwide. In some regions, the tremendous mobile growth is fueled by the lack of existing landline and cable infrastructure. In other regions, the introduction of smart phones is quickly driving mobile data traffic to become the primary mobile bandwidth consumer (some SPs have already observed that more than 85% of total mobile traffic is data traffic). MPLS-TP is viewed as a suitable technology for mobile backhaul.
无线通信是全球通信发展最快的领域之一。在一些地区，由于缺乏现有的固定电话和有线基础设施，移动电话的巨大增长得到了推动。在其他地区，智能手机的引入正在迅速推动移动数据流量成为主要的移动带宽消费者（一些SP已经观察到，超过85%的移动总流量是数据流量）。MPLS-TP被认为是一种适用于移动回程的技术。
MPLS-TP is commonly viewed as a very good fit for 2G/3G mobile backhaul. 2G (GSM/CDMA) and 3G (UMTS/HSPA/1xEVDO) mobile backhaul networks are still currently dominating the mobile infrastructure.
MPLS-TP通常被认为非常适合2G/3G移动回程。2G（GSM/CDMA）和3G（UMTS/HSPA/1xEVDO）移动回程网络目前仍然主导着移动基础设施。
The connectivity for 2G/3G networks is point to point (P2P). The logical connections have a hub-and-spoke configuration. Networks are physically constructed using a star or ring topology. In the Radio Access Network (RAN), each mobile Base Transceiver Station (BTS/Node B) is communicating with a Base Station Controller (BSC) or Radio Network Controller (RNC). These connections are often statically set up.
2G/3G网络的连接是点对点（P2P）。逻辑连接具有中心辐射配置。网络使用星形或环形拓扑结构进行物理构造。在无线接入网络（RAN）中，每个移动基站收发器站（BTS/节点B）与基站控制器（BSC）或无线网络控制器（RNC）通信。这些连接通常是静态设置的。
Hierarchical or centralized architectures are often used for pre-aggregation and aggregation layers. Each aggregation network interconnects with multiple access networks. For example, a single aggregation ring could aggregate traffic for 10 access rings with a total of 100 base stations.
分层或集中式体系结构通常用于预聚合和聚合层。每个聚合网络都与多个接入网络互连。例如，单个聚合环可以聚合10个接入环（总共100个基站）的流量。
The technology used today is largely ATM based. Mobile providers are replacing the ATM RAN infrastructure with newer packet technologies. IP RAN networks with IP/MPLS technologies are deployed today by many SPs with great success. MPLS-TP is another suitable choice for Mobile RAN. The P2P connections from base station to Radio Controller can be set statically to mimic the operation of today's RAN environments; in-band OAM and deterministic path protection can support fast failure detection and switch-over to satisfy service level agreements (SLAs). Bidirectional LSPs may help to simplify the provisioning process. The deterministic nature of MPLS-TP LSP setup can also support packet-based synchronization to maintain predictable performance regarding packet delay and jitter. The traffic-engineered and co-routed bidirectional properties of an MPLS-TP LSP
今天使用的技术主要是基于ATM的。移动提供商正在用新的分组技术取代ATM RAN基础设施。如今，许多SP都成功地部署了采用IP/MPLS技术的IP RAN网络。MPLS-TP是移动RAN的另一个合适选择。从基站到无线控制器的P2P连接可以静态设置，以模拟当今RAN环境的操作；带内OAM和确定性路径保护可以支持快速故障检测和切换，以满足服务级别协议（SLA）。双向LSP可能有助于简化资源调配过程。MPLS-TP LSP设置的确定性还可以支持基于分组的同步，以保持关于分组延迟和抖动的可预测性能。MPLS-TP LSP的流量工程和共路由双向特性
are of benefit in transporting packet-based Time and Frequency Synchronization (TFS) protocols, such as [TICTOC]. However, the choice between an external, physical-layer method or a packet-based TFS method is network dependent and thus is out of scope of this document.
在传输基于数据包的时间和频率同步（TFS）协议（如[TICTOC]）方面有好处。然而，外部物理层方法或基于分组的TFS方法之间的选择取决于网络，因此不在本文档的范围内。
One key difference between LTE and 2G/3G mobile networks is that the logical connection in LTE is a mesh, while in 2G/3G it is a P2P star. In LTE, each base station (eNB/BTS) communicates with multiple network controllers (e.g., Packet Data Network Gateway, Packet Data Network Serving Gateway, Access Service Network Gateway), and the radio elements communicate with one another for signal exchange and traffic offload to wireless or wireline infrastructures.
LTE和2G/3G移动网络之间的一个关键区别是，LTE中的逻辑连接是网状的，而2G/3G中的逻辑连接是P2P星形的。在LTE中，每个基站（eNB/BTS）与多个网络控制器（例如，分组数据网络网关、分组数据网络服务网关、接入服务网络网关）通信，并且无线电元件彼此通信以用于信号交换和向无线或有线基础设施卸载业务。
IP/MPLS has a great advantage in any-to-any connectivity environments. Thus, the use of mature IP or L3VPN technologies is particularly common in the design of an SP's LTE deployment plans.
IP/MPLS在任何对任何连接环境中都有很大的优势。因此，在SP的LTE部署计划的设计中，使用成熟的IP或L3VPN技术尤其常见。
The extended OAM functions defined in MPLS-TP, such as in-band OAM and path protection mechanisms, bring additional advantages to support SLAs. The dynamic control plane with GMPLS signaling is especially suited for the mesh environment, to support dynamic topology changes and network optimization.
MPLS-TP中定义的扩展OAM功能（如带内OAM和路径保护机制）为支持SLA带来了额外的优势。带有GMPLS信令的动态控制平面特别适合网状环境，以支持动态拓扑变化和网络优化。
Some operators are using the same model as in 2G and 3G mobile backhaul, which uses IP/MPLS in the core and MPLS-TP with static provisioning (through NMS) in aggregation and access. The reasoning is as follows: currently, the X2 traffic load in LTE networks may be a very small percentage of the total traffic. For example, one large mobile operator observed that X2 traffic was less than one percent of the total S1 traffic. Therefore, optimizing the X2 traffic may not be the design objective in this case. The X2 traffic can be carried through the same static tunnels together with the S1 traffic in the aggregation and access networks and further forwarded across the IP/MPLS core. In addition, mesh protection may be more efficient with regard to bandwidth utilization, but linear protection and ring protection are often considered simpler by some operators from the point of view of operation maintenance and troubleshooting, and so are widely deployed. In general, using MPLS-TP with static provisioning for LTE backhaul is a viable option. The design objective of using this approach is to keep the operation simple and use a common model for mobile backhaul, especially during the transition period.
一些运营商正在使用与2G和3G移动回程相同的模式，该模式在核心中使用IP/MPLS，在聚合和访问中使用MPLS-TP，并（通过NMS）进行静态资源调配。推理如下：目前，LTE网络中的X2业务负载可能占总业务的很小百分比。例如，一家大型移动运营商发现X2流量不到S1总流量的1%。因此，在这种情况下，优化X2流量可能不是设计目标。X2流量可以与聚合和接入网络中的S1流量一起通过相同的静态隧道传输，并进一步通过IP/MPLS核心转发。此外，网状保护在带宽利用率方面可能更有效，但从操作维护和故障排除的角度来看，一些运营商通常认为线性保护和环形保护更简单，因此被广泛部署。一般来说，将MPLS-TP与LTE回程的静态资源调配结合使用是一种可行的选择。使用此方法的设计目标是保持操作简单，并使用移动回程的通用模型，尤其是在过渡期。
The TFS considerations stated in Section 2.3.1 apply to the 4G/LTE mobile backhaul case as well.
第2.3.1节中所述的TFS注意事项也适用于4G/LTE移动回程情况。
The role of MPLS-TP is to provide a solution to help evolve traditional transport towards packet transport networks. It is designed to support the transport characteristics and behavior described in [RFC5654]. The primary use of MPLS-TP is largely to replace legacy transport technologies, such as SONET/SDH. MPLS-TP is not designed to replace the service support capabilities of IP/MPLS, such as L2VPN, L3VPN, IPTV, Mobile RAN, etc.
MPLS-TP的作用是提供一种解决方案，帮助传统传输向分组传输网络发展。其设计用于支持[RFC5654]中描述的传输特性和行为。MPLS-TP的主要用途主要是取代传统的传输技术，如SONET/SDH。MPLS-TP的设计目的不是取代IP/MPLS的服务支持能力，如L2VPN、L3VPN、IPTV、移动RAN等。
MPLS-TP supports two provisioning modes:
MPLS-TP支持两种资源调配模式：
- a mandatory static provisioning mode, which must be supported without dependency on dynamic routing or signaling; and
- 强制静态供应模式，必须在不依赖动态路由或信令的情况下予以支持；和
- an optional distributed dynamic control plane, which is used to enable dynamic service provisioning.
- 可选的分布式动态控制平面，用于启用动态服务供应。
The decision on which mode to use is largely dependent on the operational feasibility and the stage of network transition. Operators who are accustomed to the transport-centric operational model (e.g., NMS configuration without control plane) typically prefer the static provisioning mode. This is the most common choice in current deployments. The dynamic provisioning mode can be more powerful, but it is more suited to operators who are familiar with the operation and maintenance of IP/MPLS technologies or are ready to step up through training and planned transition.
使用哪种模式的决定在很大程度上取决于操作可行性和网络过渡阶段。习惯于以传输为中心的运营模式（例如，没有控制平面的NMS配置）的运营商通常更喜欢静态供应模式。这是当前部署中最常见的选择。动态资源调配模式可能更强大，但它更适合熟悉IP/MPLS技术的操作和维护或准备通过培训和有计划的过渡来升级的运营商。
There may also be cases where operators choose to use the combination of both modes. This is appropriate when parts of the network are provisioned in a static fashion, and other parts are controlled by dynamic signaling. This combination may also be used to transition from static provisioning to dynamic control plane.
也可能存在操作员选择使用两种模式组合的情况。当网络的部分以静态方式供应，而其他部分由动态信令控制时，这是合适的。这种组合还可用于从静态配置过渡到动态控制平面。
SPs generally recognize that standards compliance is important for lowering cost, accelerating product maturity, achieving multi-vendor interoperability, and meeting the expectations of their enterprise customers.
SPs普遍认为，遵守标准对于降低成本、加快产品成熟度、实现多供应商互操作性以及满足企业客户的期望非常重要。
MPLS-TP is a joint work between the IETF and ITU-T. In April 2008, the IETF and ITU-T jointly agreed to terminate T-MPLS and progress MPLS-TP as joint work [RFC5317]. The transport requirements are provided by the ITU-T; the protocols are developed in the IETF.
MPLS-TP是IETF和ITU-T之间的一项联合工作。2008年4月，IETF和ITU-T共同同意终止T-MPLS，并作为联合工作推进MPLS-TP[RFC5317]。传输要求由ITU-T提供；这些协议是在IETF中开发的。
End-to-end MPLS OAM consistency is highly desirable in order to enable Service Providers to deploy an end-to-end MPLS solution. As MPLS-TP adds OAM function to the MPLS toolkit, it cannot be expected that a full-function end-to-end LSP with MPLS-TP OAM can be achieved when the LSP traverses a legacy MPLS/IP core. Although it may be possible to select a subset of MPLS-TP OAM that can be gatewayed to the legacy MPLS/IP OAM, a better solution is achieved by tunneling the MPLS-TP LSP over the legacy MPLS/IP network. In that mode of operation, legacy OAM may be run on the tunnel in the core, and the tunnel endpoints may report issues in as much detail as possible to the MIPs in the MPLS-TP LSP. Note that over time it is expected that routers in the MPLS/IP core will be upgraded to fully support MPLS-TP features. Once this has occurred, it will be possible to run end-to-end MPLS-TP LSPs seamlessly across the core.
为了使服务提供商能够部署端到端MPLS解决方案，端到端MPLS OAM一致性是非常理想的。由于MPLS-TP向MPLS工具包中添加了OAM功能，因此，当LSP穿越传统MPLS/IP核心时，不可能实现具有MPLS-TP OAM的完整功能端到端LSP。尽管可以选择可以通过网关连接到传统MPLS/IP OAM的MPLS-TP OAM子集，但是通过在传统MPLS/IP网络上隧道MPLS-TP LSP可以实现更好的解决方案。在该操作模式中，遗留OAM可以在核心中的隧道上运行，并且隧道端点可以向MPLS-TP LSP中的mip尽可能详细地报告问题。请注意，随着时间的推移，预计MPLS/IP核心中的路由器将升级为完全支持MPLS-TP功能。一旦发生这种情况，就可以跨核心无缝运行端到端MPLS-TP LSP。
In general, PWs in MPLS-TP work the same as in IP/MPLS networks. Both Single-Segment PW (SS-PW) and Multi-Segment PW (MS-PW) are supported. For dynamic control plane, Targeted LDP (tLDP) is used. In static provisioning mode, PW status is a new PW OAM feature for failure notification. In addition, both directions of a PW must be bound to the same transport bidirectional LSP.
通常，MPLS-TP中的PWs与IP/MPLS网络中的PWs工作相同。支持单段PW（SS-PW）和多段PW（MS-PW）。对于动态控制平面，使用目标LDP（tLDP）。在静态配置模式下，PW状态是用于故障通知的新PW OAM功能。此外，PW的两个方向必须绑定到相同的传输双向LSP。
In the common network topology involving multi-tier rings, the design choice is between using SS-PW or MS-PW. This is not a discussion unique to MPLS-TP, as it applies to PW design in general. However, it is relevant here, since MPLS-TP is more sensitive to the operational complexities, as noted by operators. If MS-PW is used, Switching PE (S-PE) must be deployed to connect the rings. The advantage of this choice is that it provides domain isolation, which in turn facilitates troubleshooting and allows for faster PW failure recovery. On the other hand, the disadvantage of using S-PE is that it adds more complexity. Using SS-PW is simpler, since it does not require S-PEs, but it is less efficient because the paths across primary and secondary rings are longer. If operational simplicity is a higher priority, some SPs choose SS-PW.
在涉及多层环的常见网络拓扑中，设计选择是使用SS-PW还是MS-PW。这不是MPLS-TP独有的讨论，因为它通常适用于PW设计。然而，正如运营商指出的那样，MPLS-TP对操作复杂性更为敏感，因此在这里是相关的。如果使用MS-PW，则必须部署交换PE（S-PE）以连接环。这种选择的优点是它提供了域隔离，这反过来有助于故障排除，并允许更快的PW故障恢复。另一方面，使用S-PE的缺点是它增加了更多的复杂性。使用SS-PW比较简单，因为它不需要S-PEs，但效率较低，因为穿过主环和次环的路径较长。如果操作简单是更高的优先级，一些SP会选择SS-PW。
Another design trade-off is whether to use PW protection in addition to LSP protection or rely solely on LSP protection. When the MPLS-TP LSPs are protected, if the working LSP fails, the protecting LSP
另一个设计权衡是在LSP保护之外使用PW保护还是仅依赖LSP保护。当MPLS-TP LSP受到保护时，如果工作LSP失败，则保护LSP
assures that the connectivity is maintained and the PW is not impacted. However, in the case of simultaneous failure of both the working and protecting LSPs, the attached PW would fail. By adding PW protection and attaching the protecting PW to a diverse LSP not in the same Shared Risk Link Group (SRLG), the PW is protected even when the primary PW fails. Clearly, using PW protection adds considerably more complexity and resource usage, and thus operators often may choose not to use it and consider protection against a single point of failure as sufficient.
确保保持连接且PW不受影响。然而，在工作和保护LSP同时失效的情况下，连接的PW将失效。通过添加PW保护并将保护PW连接到不在同一共享风险链接组（SRLG）中的不同LSP，即使主PW出现故障，PW也会得到保护。显然，使用PW保护增加了相当多的复杂性和资源使用率，因此运营商通常可以选择不使用它，并考虑保护对单个故障点的保护。
MPLS-TP provides both proactive and on-demand OAM tools. As a proactive OAM fault management tool, BFD Connectivity Check (CC) can be sent at regular intervals for Connectivity Check; three (or a configurable number) of missed CC messages can trigger the failure protection switch-over. BFD sessions are configured for both working and protecting LSPs.
MPLS-TP提供了主动式和按需式OAM工具。作为一种主动式OAM故障管理工具，BFD连接检查（CC）可以定期发送以进行连接检查；三条（或一个可配置数量）丢失的CC消息可触发故障保护切换。BFD会话配置为工作LSP和保护LSP。
A design decision is choosing the value of the BFD CC interval. The shorter the interval, the faster the detection time is, but also the higher the resource utilization is. The proper value depends on the application and the service needs, as well as the protection mechanism provided at the lower layer.
设计决策是选择BFD CC间隔的值。间隔越短，检测时间越快，但资源利用率也越高。适当的值取决于应用程序和服务需求，以及在较低层提供的保护机制。
As an on-demand OAM fault management mechanism (for example, when there is a fiber cut), a Link Down Indication (LDI) message [RFC6427] can be generated from the failure point and propagated to the Maintenance Entity Group End Points (MEPs) to trigger immediate switch-over from working to protecting path. An Alarm Indication Signal (AIS) can be propagated from the Maintenance Entity Group Intermediate Point (MIP) to the MEPs for alarm suppression.
作为一种按需OAM故障管理机制（例如，当光纤中断时），可以从故障点生成链路断开指示（LDI）消息[RFC6427]，并传播到维护实体组端点（MEP），以触发从工作路径到保护路径的立即切换。报警指示信号（AIS）可从维修实体组中间点（MIP）传播到MEP，以抑制报警。
In general, both proactive and on-demand OAM tools should be enabled to guarantee short switch-over times.
一般来说，应启用主动式和按需式OAM工具，以保证较短的切换时间。
Since IP/MPLS is largely deployed in most SPs' networks, MPLS-TP and IP/MPLS interworking is inevitable if not a reality. However, interworking discussion is out of the scope of this document; it is for further study.
由于IP/MPLS主要部署在大多数SP的网络中，因此MPLS-TP和IP/MPLS互通即使不是现实，也是不可避免的。但是，互通式讨论不在本文件范围内；这是为了进一步研究。
Under the use case of Metro access and aggregation, in the scenario where some of the access equipment is placed in facilities not owned by the SP, the static provisioning mode of MPLS-TP is often preferred over the control-plane option because it eliminates the possibility of a control-plane attack, which may potentially impact the whole network. This scenario falls into the Security Reference Model 2 as described in [RFC6941].
在城域接入和聚合的使用情况下，在某些接入设备放置在SP不拥有的设施中的场景中，MPLS-TP的静态配置模式通常优于控制平面选项，因为它消除了控制平面攻击的可能性，这可能会影响整个网络。此场景属于[RFC6941]中描述的安全参考模型2。
Similar location issues apply to the mobile use cases since equipment is often placed in remote and outdoor environment, which can increase the risk of unauthorized access to the equipment.
类似的位置问题也适用于移动用例，因为设备通常放置在远程和室外环境中，这会增加未经授权访问设备的风险。
In general, NMS access can be a common point of attack in all MPLS-TP use cases, and attacks to GAL or G-ACh are unique security threats to MPLS-TP. The MPLS-TP security considerations are discussed in the MPLS-TP security framework [RFC6941]. General security considerations for MPLS and GMPLS networks are addressed in "Security Framework for MPLS and GMPLS Networks" [RFC5920].
一般来说，在所有MPLS-TP用例中，NMS访问可能是一个常见的攻击点，而对GAL或G-ACh的攻击是MPLS-TP特有的安全威胁。MPLS-TP安全注意事项在MPLS-TP安全框架[RFC6941]中讨论。MPLS和GMPLS网络的一般安全注意事项见“MPLS和GMPLS网络的安全框架”[RFC5920]。
The authors wish to thank Adrian Farrel for his review as Routing Area Director and his continued support and guidance. Adrian's detailed comments and suggestions were of great help for improving the quality of this document. In addition, the authors would like to thank the following individuals: Loa Andersson for his continued support and guidance; Weiqiang Cheng for his helpful input on LTE mobile backhaul based on his knowledge and experience in real world deployment; Stewart Bryant for his text contribution on timing; Russ Housley for his improvement suggestions; Andrew Malis for his support and use case discussion; Pablo Frank, Lucy Yong, Huub van Helvoort, Tom Petch, Curtis Villamizar, and Paul Doolan for their comments and suggestions; and Joseph Yee and Miguel Garcia for their APPSDIR and Gen-ART reviews and comments, respectively.
作者希望感谢阿德里安·法雷尔（Adrian Farrel）作为路由区域总监所做的评论以及他持续的支持和指导。阿德里安的详细评论和建议对提高本文件的质量有很大帮助。此外，作者还要感谢以下个人：Loa Andersson对他的持续支持和指导；郑维强，感谢他基于其在现实世界部署方面的知识和经验，对LTE移动回程的有益投入；斯图尔特·布莱恩特在时间上的文字贡献；Russ Housley提出了改进建议；Andrew Malis的支持和用例讨论；巴勃罗·弗兰克、露西·杨、胡布·范·赫尔沃特、汤姆·佩奇、柯蒂斯·维拉米扎和保罗·杜兰，感谢他们的评论和建议；以及Joseph Yee和Miguel Garcia的APPSDIR和Gen艺术评论和评论。
[RFC5654] Niven-Jenkins, B., Ed., Brungard, D., Ed., Betts, M., Ed., Sprecher, N., and S. Ueno, "Requirements of an MPLS Transport Profile", RFC 5654, September 2009.
[RFC5654]Niven Jenkins，B.，Ed.，Brungard，D.，Ed.，Betts，M.，Ed.，Sprecher，N.，和S.Ueno，“MPLS传输配置文件的要求”，RFC 56542009年9月。
[RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS Networks", RFC 5920, July 2010.
[RFC5920]方，L.，编辑，“MPLS和GMPLS网络的安全框架”，RFC 5920，2010年7月。
[RFC5921] Bocci, M., Ed., Bryant, S., Ed., Frost, D., Ed., Levrau, L., and L. Berger, "A Framework for MPLS in Transport Networks", RFC 5921, July 2010.
[RFC5921]Bocci，M.，Ed.，Bryant，S.，Ed.，Frost，D.，Ed.，Levrau，L.，和L.Berger，“传输网络中MPLS的框架”，RFC 59212010年7月。
[RFC6426] Gray, E., Bahadur, N., Boutros, S., and R. Aggarwal, "MPLS On-Demand Connectivity Verification and Route Tracing", RFC 6426, November 2011.
[RFC6426]Gray，E.，Bahadur，N.，Boutros，S.，和R.Aggarwal，“MPLS按需连接验证和路由跟踪”，RFC 6426，2011年11月。
[RFC6427] Swallow, G., Ed., Fulignoli, A., Ed., Vigoureux, M., Ed., Boutros, S., and D. Ward, "MPLS Fault Management Operations, Administration, and Maintenance (OAM)", RFC 6427, November 2011.
[RFC6427]Swallow，G.，Ed.，Fulignoli，A.，Ed.，Vigoureux，M.，Ed.，Boutros，S.，和D.Ward，“MPLS故障管理操作、管理和维护（OAM）”，RFC 64272011年11月。
[RFC6428] Allan, D., Ed., Swallow Ed., G., and J. Drake Ed., "Proactive Connectivity Verification, Continuity Check, and Remote Defect Indication for the MPLS Transport Profile", RFC 6428, November 2011.
[RFC6428]Allan，D.，Ed.，Swallow Ed.，G.，和J.Drake Ed.“MPLS传输配置文件的主动连接验证、连续性检查和远程缺陷指示”，RFC 6428，2011年11月。
[RFC5317] Bryant, S., Ed., and L. Andersson, Ed., "Joint Working Team (JWT) Report on MPLS Architectural Considerations for a Transport Profile", RFC 5317, February 2009.
[RFC5317]Bryant，S.，Ed.，和L.Andersson，Ed.，“联合工作组（JWT）关于传输配置文件的MPLS体系结构考虑的报告”，RFC 53172009年2月。
[RFC6372] Sprecher, N., Ed., and A. Farrel, Ed., "MPLS Transport Profile (MPLS-TP) Survivability Framework", RFC 6372, September 2011.
[RFC6372]Sprecher，N.，Ed.，和A.Farrel，Ed.，“MPLS传输配置文件（MPLS-TP）生存能力框架”，RFC 6372，2011年9月。
[RFC6669] Sprecher, N. and L. Fang, "An Overview of the Operations, Administration, and Maintenance (OAM) Toolset for MPLS-Based Transport Networks", RFC 6669, July 2012.
[RFC6669]Sprecher，N.和L.Fang，“基于MPLS的传输网络的操作、管理和维护（OAM）工具集概述”，RFC 6669，2012年7月。
[RFC6941] Fang, L., Ed., Niven-Jenkins, B., Ed., Mansfield, S., Ed., and R. Graveman, Ed., "MPLS Transport Profile (MPLS-TP) Security Framework", RFC 6941, April 2013.
[RFC6941]Fang，L.，Ed.，Niven Jenkins，B.，Ed.，Mansfield，S.，Ed.，和R.Graveman，Ed.，“MPLS传输配置文件（MPLS-TP）安全框架”，RFC 69412013年4月。
[TICTOC] Davari, S., Oren, A., Bhatia, M., Roberts, P., Montini, L., and L. Martini, "Transporting Timing messages over MPLS Networks", Work in Progress, June 2013.
[TICTOC]Davari，S.，Oren，A.，Bhatia，M.，Roberts，P.，Montini，L.，和L.Martini，“通过MPLS网络传输定时消息”，正在进行的工作，2013年6月。
Kam Lee Yap XO Communications 13865 Sunrise Valley Drive Herndon, VA 20171 United States EMail: klyap@xo.com
Kam Lee Yap XO Communications 13865日出谷大道Herndon，弗吉尼亚州20171美国电子邮件：klyap@xo.com
Dan Frost Cisco Systems, Inc. United Kingdom EMail: danfrost@cisco.com
Dan Frost Cisco Systems，Inc.英国电子邮件：danfrost@cisco.com
Henry Yu TW Telecom 10475 Park Meadow Dr. Littleton, CO 80124 United States EMail: henry.yu@twtelecom.com
Henry Yu TW Telecom 10475 Park Meadow，CO.Littleton博士，邮编：80124美国电子邮件：Henry。yu@twtelecom.com
Jian Ping Zhang China Telecom, Shanghai Room 3402, 211 Shi Ji Da Dao Pu Dong District, Shanghai China EMail: zhangjp@shtel.com.cn
张建平中国电信，上海，中国上海市浦东区世纪大道211号3402室电子邮件：zhangjp@shtel.com.cn
Lei Wang Lime Networks Strandveien 30, 1366 Lysaker Norway EMail: lei.wang@limenetworks.no
Lei Wang Lime Networks Strandveien 301366 Lysaker Norway电子邮件：Lei。wang@limenetworks.no
Mach (Guoyi) Chen Huawei Technologies Co., Ltd. No. 3 Xinxi Road Shangdi Information Industry Base Hai-Dian District, Beijing 100085 China EMail: mach@huawei.com
马赫（国一）陈华为技术有限公司北京市海淀区上地信息产业基地新西路3号邮编：100085中国电子邮件：mach@huawei.com
Nurit Sprecher Nokia Siemens Networks 3 Hanagar St. Neve Ne'eman B Hod Hasharon, 45241 Israel EMail: nurit.sprecher@nsn.com
Nurit Sprecher诺基亚西门子网络3号Hanagar St.Neve'eman B Hod Hasharon，45241以色列电子邮件：Nurit。sprecher@nsn.com
Authors' Addresses
作者地址
Luyuan Fang (editor) Cisco Systems, Inc. 111 Wood Ave. South Iselin, NJ 08830 United States EMail: lufang@cisco.com
方陆元（编辑）思科系统有限公司，地址：美国新泽西州伊塞林南伍德大道111号，邮编：08830电子邮件：lufang@cisco.com
Nabil Bitar Verizon 40 Sylvan Road Waltham, MA 02145 United States EMail: nabil.bitar@verizon.com
Nabil Bitar Verizon 40 Sylvan Road Waltham，马萨诸塞州02145美国电子邮件：Nabil。bitar@verizon.com
Raymond Zhang Alcatel-Lucent 701 Middlefield Road Mountain View, CA 94043 United States EMail: raymond.zhang@alcatel-lucent.com
Raymond Zhang阿尔卡特朗讯701美国加利福尼亚州米德菲尔德路山景城94043电子邮件：Raymond。zhang@alcatel-朗讯网
Masahiro Daikoku KDDI Corporation 3-11-11.Iidabashi, Chiyodaku, Tokyo Japan EMail: ms-daikoku@kddi.com
Masahiro Daikoku KDDI Corporation 3-11-11.Iidabashi，Chiyodaku，Tokyo Japan电子邮件：ms-daikoku@kddi.com
Ping Pan Infinera United States EMail: ppan@infinera.com
平盘英菲纳美国电子邮件：ppan@infinera.com