Network Working Group M. Seaman
Request for Comments: 2815 Telseon
Category: Standards Track A. Smith
Extreme Networks
E. Crawley
Unisphere Solutions
J. Wroclawski
MIT LCS
May 2000
Network Working Group M. Seaman
Request for Comments: 2815 Telseon
Category: Standards Track A. Smith
Extreme Networks
E. Crawley
Unisphere Solutions
J. Wroclawski
MIT LCS
May 2000
Integrated Service Mappings on IEEE 802 Networks
ieee802网络上的综合业务映射
Status of this Memo
本备忘录的状况
This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.
本文件规定了互联网社区的互联网标准跟踪协议，并要求进行讨论和提出改进建议。有关本协议的标准化状态和状态，请参考当前版本的“互联网官方协议标准”（STD 1）。本备忘录的分发不受限制。
Copyright Notice
版权公告
Copyright (C) The Internet Society (2000). All Rights Reserved.
版权所有（C）互联网协会（2000年）。版权所有。
Abstract
摘要
This document describes mappings of IETF Integrated Services over LANs built from IEEE 802 network segments which may be interconnected by IEEE 802.1D MAC Bridges (switches). It describes parameter mappings for supporting Controlled Load and Guaranteed Service using the inherent capabilities of relevant IEEE 802 technologies and, in particular, 802.1D-1998 queuing features in switches.
本文档描述了IETF综合服务在局域网上的映射，局域网由IEEE 802网段构建，这些网段可由IEEE 802.1D MAC网桥（交换机）互连。它描述了使用相关IEEE 802技术的固有功能，特别是交换机中的802.1D-1998排队功能，支持受控负载和保证服务的参数映射。
These mappings are one component of the Integrated Services over IEEE 802 LANs framework.
这些映射是IEEE 802 LAN框架上集成服务的一个组成部分。
Table of Contents
目录
1 Introduction ............................................... 2
2 Flow Identification and Traffic Class Selection ............ 3
3 Choosing a flow's IEEE 802 user_priority class ............. 5
3.1 Context of admission control and delay bounds ............ 6
3.2 Default service mappings ................................. 7
3.3 Discussion ............................................... 9
4 Computation of integrated services characterization parameters
by IEEE 802 devices .....................................10
4.1 General characterization parameters ......................10
4.2 Parameters to implement Guaranteed Service ...............11
4.3 Parameters to implement Controlled Load ..................11
4.4 Parameters to implement Best Effort ......................12
5 Merging of RSVP/SBM objects ................................12
6 Applicability of these service mappings ....................13
7 References .................................................14
8 Security Considerations ....................................15
9 Acknowledgments ............................................15
10 Authors' Addresses ........................................16
11 Full Copyright Statement ..................................17
1 Introduction ............................................... 2
2 Flow Identification and Traffic Class Selection ............ 3
3 Choosing a flow's IEEE 802 user_priority class ............. 5
3.1 Context of admission control and delay bounds ............ 6
3.2 Default service mappings ................................. 7
3.3 Discussion ............................................... 9
4 Computation of integrated services characterization parameters
by IEEE 802 devices .....................................10
4.1 General characterization parameters ......................10
4.2 Parameters to implement Guaranteed Service ...............11
4.3 Parameters to implement Controlled Load ..................11
4.4 Parameters to implement Best Effort ......................12
5 Merging of RSVP/SBM objects ................................12
6 Applicability of these service mappings ....................13
7 References .................................................14
8 Security Considerations ....................................15
9 Acknowledgments ............................................15
10 Authors' Addresses ........................................16
11 Full Copyright Statement ..................................17
The IEEE 802.1 Interworking Task Group has developed a set of enhancements to the basic MAC Service provided in Bridged Local Area Networks (a.k.a. "switched LANs"). As a supplement to the original IEEE MAC Bridges standard, IEEE 802.1D-1990 [802.1D-ORIG], the updated IEEE 802.1D-1998 [802.1D] proposes differential traffic class queuing in switches. The IEEE 802.1Q specification [802.1Q] extends the capabilities of Ethernet/802.3 media to carry a traffic class indicator, or "user_priority" field, within data frames.
IEEE 802.1互通任务组已开发了一套增强功能，用于桥接局域网（又称“交换局域网”）中提供的基本MAC服务。作为对原始IEEE MAC网桥标准IEEE 802.1D-1990[802.1D-ORIG]的补充，更新的IEEE 802.1D-1998[802.1D]提出了交换机中的差分流量等级排队。IEEE 802.1Q规范[802.1Q]扩展了以太网/802.3媒体的功能，以在数据帧内携带流量等级指示器或“用户优先级”字段。
The availability of this differential traffic queuing, together with additional mechanisms to provide admission control and signaling, allows IEEE 802 networks to support a close approximation of the IETF Integrated Services capabilities [CL][GS]. This document describes methods for mapping the service classes and parameters of the IETF model into IEEE 802.1D network parameters. A companion document [SBM] describes a signaling protocol for use with these mappings. It is recommended that readers be familiar with the overall framework in which these mappings and signaling protocol are expected to be used; this framework is described fully in [IS802FRAME].
这种差分业务排队的可用性，以及提供准入控制和信令的附加机制，使IEEE 802网络能够支持IETF综合业务能力[CL][GS]的近似值。本文档描述了将IETF模型的服务类和参数映射为IEEE 802.1D网络参数的方法。附带文档[SBM]描述了用于这些映射的信令协议。建议读者熟悉预期使用这些映射和信令协议的总体框架；这个框架在[IS802FRAME]中有完整的描述。
Within this document, Section 2 describes the method by which end systems and routers bordering the IEEE Layer-2 cloud learn what traffic class should be used for each data flow's packets. Section 3 describes the approach recommended to map IP-level traffic flows to
在本文档中，第2节描述了与IEEE第2层云相邻的终端系统和路由器了解每个数据流的数据包应使用何种流量类别的方法。第3节描述了将IP级流量映射到
IEEE traffic classes within the Layer 2 network. Section 4 describes the computation of Characterization Parameters by the layer 2 network. The remaining sections discuss some particular issues with the use of the RSVP/SBM signaling protocols, and describe the applicability of all of the above to different layer 2 network topologies.
第2层网络内的IEEE流量等级。第4节描述了通过第2层网络计算表征参数。其余部分讨论使用RSVP/SBM信令协议的一些特定问题，并描述上述所有协议对不同的第2层网络拓扑的适用性。
One model for supporting integrated services over specific link layers treats layer-2 devices very much as a special case of routers. In this model, switches and other devices along the data path make packet handling decisions based on the RSVP flow and filter specifications, and use these specifications to classify the corresponding data packets. The specifications could either be used directly, or could be used indirectly by mapping each RSVP session onto a layer-2 construct such as an ATM virtual circuit.
一种支持特定链路层上集成服务的模型将第2层设备视为路由器的特例。在该模型中，交换机和数据路径上的其他设备根据RSVP流和过滤器规范做出数据包处理决策，并使用这些规范对相应的数据包进行分类。规范可以直接使用，也可以通过将每个RSVP会话映射到第二层结构（如ATM虚拟电路）来间接使用。
This approach is inappropriate for use in the IEEE 802 environment. Filtering to the per-flow level becomes expensive with increasing switch speed; devices with such filtering capabilities are likely to have a very similar implementation complexity to IP routers, and may not make use of simpler mechanisms such as 802.1D user priority.
此方法不适合在IEEE 802环境中使用。随着开关速度的增加，过滤到每流量水平变得昂贵；具有此类过滤功能的设备可能具有与IP路由器非常相似的实现复杂性，并且可能不会使用更简单的机制，例如802.1D用户优先级。
The Integrated Services over IEEE 802 LANs framework [IS802FRAME] and this document use an "aggregated flow" approach based on use of layer-2 traffic classes. In this model, each arriving flow is assigned to one of the available classes for the duration of the flow and traverses the 802 cloud in this class. Traffic flows requiring similar service are grouped together into a single class, while the system's admission control and class selection rules ensure that the service requirements for flows in each of the classes are met. In many situations this is a viable intermediate point between no QoS control and full router-type integrated services. The approach can work effectively even with switches implementing only the simplest differential traffic classification capability specified in the 802.1D model. In the aggregated flow model, traffic arriving at the boundary of a layer-2 cloud is tagged by the boundary device (end host or border router) with an appropriate traffic class, represented as an 802.1D "user_priority" value. Two fundamental questions are "who determines the correspondence between IP-level traffic flows and link-level classes?" and "how is this correspondence conveyed to the boundary devices that must mark the data frames?"
IEEE 802 LAN框架[IS802FRAME]上的综合业务和本文档使用基于第2层流量类别的“聚合流”方法。在这个模型中，每个到达的流在流的持续时间内被分配到一个可用的类，并在这个类中穿越802云。需要类似服务的交通流被分组到一个类别中，而系统的准入控制和类别选择规则确保满足每个类别中的交通流的服务要求。在许多情况下，这是一个可行的中间点，介于无QoS控制和完全路由器类型的集成服务之间。即使交换机只实现802.1D模型中规定的最简单的差分流量分类功能，该方法也能有效工作。在聚合流模型中，到达第二层云边界的流量由边界设备（终端主机或边界路由器）使用适当的流量类别进行标记，表示为802.1D“用户优先级”值。两个基本问题是“谁决定IP级流量和链路级类别之间的对应关系？”和“这种对应关系如何传递到必须标记数据帧的边界设备？”
One approach to answering these questions would be for the meanings of the classes to be universally defined. This document would then standardize the meanings of a set of classes; e.g., 1 = best effort, 2 = 100 ms peak delay target, 3 = 10 ms peak delay target, 4 = 1 ms
回答这些问题的一种方法是对类的含义进行普遍定义。然后，本文件将标准化一组类别的含义；e、 例如，1=最大努力，2=100毫秒峰值延迟目标，3=10毫秒峰值延迟目标，4=1毫秒
peak delay target, etc. The meanings of these universally defined classes could then be encoded directly in end stations, and the flow-to-class mappings computed directly in these devices.
峰值延迟目标等。这些普遍定义的类的含义可以直接在终端站中编码，流到类的映射可以直接在这些设备中计算。
This universal definition approach would be simple to implement, but is too rigid to map the wide range of possible user requirements onto the limited number of available 802.1D classes. The model described in [IS802FRAME] uses a more flexible mapping: clients ask "the network" which user_priority traffic class to use for a given traffic flow, as categorized by its flow-spec and layer-2 endpoints. The network provides a value back to the requester that is appropriate considering the current network topology, load conditions, other admitted flows, etc. The task of configuring switches with this mapping (e.g., through network management, a switch-switch protocol or via some network-wide QoS-mapping directory service) is an order of magnitude less complex than performing the same function in end stations. Also, when new services (or other network reconfigurations) are added to such a network, the network elements will typically be the ones to be upgraded with new queuing algorithms etc. and can be provided with new mappings at this time.
这种通用定义方法易于实现，但过于严格，无法将广泛的可能用户需求映射到数量有限的可用802.1D类上。[IS802FRAME]中描述的模型使用了一种更灵活的映射：客户机询问“网络”，对于给定的流量流，要使用哪个用户优先级流量类别，按照其流量规范和第2层端点进行分类。考虑到当前网络拓扑、负载条件、其他允许流等，网络向请求者提供适当的值。使用此映射配置交换机的任务（例如，通过网络管理、交换机交换机协议或通过某些网络范围的QoS映射目录服务）与在终端站中执行相同功能相比，其复杂程度要低一个数量级。此外，当新的服务（或其他网络重新配置）被添加到这样的网络中时，网络元素通常将是使用新的排队算法等进行升级的元素，并且此时可以提供新的映射。
In the current model it is assumed that all data packets of a flow are assigned to the same traffic class for the duration of the flow: the characteristics of the MAC service, as defined by Clause 6 of [802.1D], then ensure the ordering of the data packets of the flow between adjacent Layer 3 routers. This is usually desirable to avoid potential re-ordering problems as discussed in [IS802FRAME] and [CL]. Note that there are some scenarios where it might be desirable to send conforming data traffic in one traffic class and non-conforming traffic for the same flow in a different, lower traffic class: such a division into separate traffic classes is for future study. When a new session or "flow" requiring QoS support is created, a client must ask "the network" which traffic class (IEEE 802 user_priority) to use for a given traffic flow, so that it can label the packets of the flow as it places them into the network. A request/response protocol is needed between client and network to return this information. The request can be piggy-backed onto an admission control request and the response can be piggy-backed onto an admission control acknowledgment. This "one pass" assignment has the benefit of completing the admission control transaction in a timely way and reducing the exposure to changing conditions that could occur if clients cached the knowledge for extensive periods. A set of extensions to the RSVP protocol for communicating this information have been defined [SBM].
在当前模型中，假设流的所有数据包在流的持续时间内分配给相同的流量类别：MAC服务的特征，如[802.1D]第6条所定义，然后确保相邻第3层路由器之间流的数据包的顺序。这通常是为了避免[IS802FRAME]和[CL]中讨论的潜在重新排序问题。注意，在某些情况下，可能需要在一个流量类别中发送一致数据流量，在不同的较低流量类别中发送相同流量的不一致数据流量：这样划分为单独的流量类别是为了将来的研究。当创建需要QoS支持的新会话或“流”时，客户端必须询问“网络”给定流量使用哪种流量类别（IEEE 802 user_priority），以便在将流量的数据包放入网络时标记这些数据包。客户端和网络之间需要一个请求/响应协议来返回此信息。该请求可以背载于准入控制请求，而响应可以背载于准入控制确认。这种“一次通过”的分配有利于及时完成准入控制事务，并减少客户在长时间缓存知识的情况下可能发生的变化。已定义了一组RSVP协议的扩展，用于传输此信息[SBM]。
The network (i.e., the first network element encountered downstream from the client) must then answer the following questions:
然后，网络（即客户端下游遇到的第一个网元）必须回答以下问题：
1. Which of the available traffic classes would be appropriate for this flow?
1. 以下哪种可用流量类别适合此流量？
In general, a newly arriving flow might be assigned to a number of classes. For example, if 10ms of delay is acceptable, the flow could potentially be assigned to either a 10ms delay class or a 1ms delay class. This packing problem is quite difficult to solve if the target parameters of the classes are allowed to change dynamically as flows arrive and depart. It is quite simple if the target parameters of each class is held fixed, and the class table is simply searched to find a class appropriate for the arriving flow. This document adopts the latter approach.
通常，一个新到达的流可能被分配给多个类。例如，如果10ms的延迟是可接受的，则流可能被分配到10ms延迟类或1ms延迟类。如果允许类的目标参数随着流的到达和离开而动态变化，那么这个打包问题就很难解决。如果每个类的目标参数保持不变，并且简单地搜索类表以找到适合到达流的类，那么这是非常简单的。本文件采用后一种方法。
2. Of the appropriate traffic classes, which if any have enough capacity available to accept the new flow?
2. 适当的流量类别中，哪些（如果有的话）有足够的可用容量来接受新流量？
This is the admission control problem. It is necessary to compare the level of traffic currently assigned to each class with the available level of network resources (bandwidth, buffers, etc), to ensure that adding the new flow to the class will not cause the class's performance to go below its target values. This problem is compounded because in a priority queuing system adding traffic to a higher-priority class can affect the performance of lower-priority classes. The admission control algorithm for a system using the default 802 priority behavior must be reasonably sophisticated to provide acceptable results.
这就是准入控制问题。有必要将当前分配给每个类的流量级别与可用的网络资源级别（带宽、缓冲区等）进行比较，以确保向该类添加新流量不会导致该类的性能低于其目标值。这个问题更加复杂，因为在优先级排队系统中，向高优先级类别添加流量会影响低优先级类别的性能。使用默认802优先级行为的系统的准入控制算法必须相当复杂，才能提供可接受的结果。
If an acceptable class is found, the network returns the chosen user_priority value to the client.
如果找到可接受的类，则网络会将所选的用户优先级值返回给客户端。
Note that the client may be an end station, a router at the edge of the layer 2 network, or a first switch acting as a proxy for a device that does not participate in these protocols for whatever reason. Note also that a device e.g., a server or router may choose to implement both the "client" as well as the "network" portion of this model so that it can select its own user_priority values. Such an implementation would generally be discouraged unless the device has a close tie-in with the network topology and resource allocation policies. It may, however, work acceptably in cases where there is known over-provisioning of resources.
注意，客户端可以是终端站、位于第2层网络边缘的路由器，或者作为出于任何原因不参与这些协议的设备的代理的第一交换机。还要注意，例如服务器或路由器的设备可以选择实现该模型的“客户端”和“网络”部分，以便它可以选择自己的用户优先级值。除非设备与网络拓扑和资源分配策略紧密结合，否则通常不鼓励这种实现。然而，在已知资源过度供应的情况下，它可能可以正常工作。
This section describes the method by which IP-level flows are mapped into appropriate IEEE user_priority classes. The IP-level services considered are Best Effort, Controlled Load, and Guaranteed Service.
本节描述了将IP级流映射到适当的IEEE用户优先级类的方法。所考虑的IP级别服务是尽力而为、控制负载和保证服务。
The major issue is that admission control requests and application requirements are specified in terms of a multidimensional vector of parameters e.g., bandwidth, delay, jitter, service class. This multidimensional space must be mapped onto a set of traffic classes whose default behavior in L2 switches is unidimensional (i.e., strict priority default queuing). This priority queuing alone can provide only relative ordering between traffic classes. It can neither enforce an absolute (quantifiable) delay bound for a traffic class, nor can it discriminate amongst Int-Serv flows within the aggregate in a traffic class. Therefore, it cannot provide the absolute control of packet loss and delay required for individual Int-Serv flows.
主要问题是，准入控制请求和应用程序要求是根据多维参数向量来指定的，例如带宽、延迟、抖动、服务级别。这个多维空间必须映射到一组流量类上，这些流量类在L2交换机中的默认行为是一维的（即严格优先级默认队列）。仅此优先级队列就只能提供流量类别之间的相对顺序。它既不能为一个流量类别强制执行一个绝对（可量化）延迟界限，也不能在一个流量类别的聚合中区分Int-Serv流。因此，它不能提供对单个Int-Serv流所需的数据包丢失和延迟的绝对控制。
To provide absolute control of loss and delay three things must occur:
要绝对控制损失和延误，必须做到三件事：
(1) The amount of bandwidth available to the QoS-controlled flows must be known, and the number of flows admitted to the network (allowed to use the bandwidth) must be limited.
(1) 必须知道QoS控制流的可用带宽量，并且必须限制允许进入网络（允许使用带宽）的流的数量。
(2) A traffic scheduling mechanism is needed to give preferential service to flows with lower delay targets.
(2) 需要一种流量调度机制为具有较低延迟目标的流提供优先服务。
(3) Some mechanism must ensure that best-effort flows and QoS controlled flows that are exceeding their Tspecs do not damage the quality of service delivered to in-Tspec QoS controlled flows. This mechanism could be part of the traffic scheduler, or it could be a separate policing mechanism.
(3) 某些机制必须确保最大努力流和超出其Tspec QoS控制流的QoS控制流不会损害在Tspec QoS控制流中提供给的服务质量。该机制可以是流量调度器的一部分，也可以是一个单独的策略机制。
For IEEE 802 networks, the first function (admission control) is provided by a Subnet Bandwidth Manager, as discussed below. We use the link-level user_priority mechanism at each switch and bridge to implement the second function (preferential service to flows with lower delay targets). Because a simple priority scheduler cannot provide policing (function three), policing for IEEE networks is generally implemented at the edge of the network by a layer-3 device. When this policing is performed only at the edges of the network it is of necessity approximate. This issue is discussed further in [IS802FRAME].
对于IEEE 802网络，第一个功能（许可控制）由子网带宽管理器提供，如下所述。我们在每个交换机和网桥上使用链路级用户_优先级机制来实现第二个功能（对具有较低延迟目标的流的优先服务）。由于简单的优先级调度器无法提供策略（功能3），IEEE网络的策略通常由第3层设备在网络边缘实现。当仅在网络边缘执行此策略时，它是必需的。这个问题将在[IS802框架]中进一步讨论。
As described above, it is the combination of priority-based scheduling and admission control that creates quantified delay bounds. Thus, any attempt to quantify the delay bounds expected by a given traffic class has to made in the context of the admission control elements. Section 6 of the framework [IS802FRAME] provides for two different models of admission control - centralized or distributed Bandwidth Allocators.
如上所述，正是基于优先级的调度和接纳控制的组合创建了量化的延迟边界。因此，必须在接纳控制元素的上下文中进行量化给定业务类别所期望的延迟边界的任何尝试。框架[IS802FRAME]的第6节提供了两种不同的接纳控制模型——集中式或分布式带宽分配器。
It is important to note that in this approach it is the admission control algorithm that determines which of the Int-Serv services is being offered. Given a set of priority classes with delay targets, a relatively simple admission control algorithm can place flows into classes so that the bandwidth and delay behavior experienced by each flow corresponds to the requirements of the Controlled-Load service, but cannot offer the higher assurance of the Guaranteed service. To offer the Guaranteed service, the admission control algorithm must be much more stringent in its allocation of resources, and must also compute the C and D error terms required of this service.
需要注意的是，在这种方法中，是准入控制算法决定了提供哪种Int-Serv服务。给定一组具有延迟目标的优先级类，一个相对简单的接纳控制算法可以将流放入类中，以便每个流所经历的带宽和延迟行为对应于受控负载服务的要求，但不能提供更高的保证服务。为了提供有保证的服务，接纳控制算法必须在其资源分配方面更加严格，并且还必须计算此服务所需的C和D错误项。
A delay bound can only be realized at the admission control element itself so any delay numbers attached to a traffic class represent the delay that a single element can allow for. That element may represent a whole L2 domain or just a single L2 segment.
延迟界限只能在准入控制元素本身实现，因此附加到业务类别的任何延迟编号表示单个元素可以允许的延迟。该元素可以表示整个L2域，也可以仅表示单个L2段。
With either admission control model, the delay bound has no scope outside of a L2 domain. The only requirement is that it be understood by all Bandwidth Allocators in the L2 domain and, for example, be exported as C and D terms to L3 devices implementing the Guaranteed Service. Thus, the end-to-end delay experienced by a flow can only be characterized by summing along the path using the usual RSVP mechanisms.
无论采用哪种接纳控制模型，延迟界限都不在L2域之外。唯一的要求是L2域中的所有带宽分配器都能理解它，例如，将它作为C和D术语导出到实现保证服务的L3设备。因此，流所经历的端到端延迟只能通过使用通常的RSVP机制沿路径求和来表征。
Table 1 presents the default mapping from delay targets to IEEE 802.1 user_priority classes. However, these mappings must be viewed as defaults, and must be changeable.
表1给出了从延迟目标到IEEE 802.1用户_优先级类的默认映射。但是，这些映射必须视为默认值，并且必须是可更改的。
In order to simplify the task of changing mappings, this mapping table is held by *switches* (and routers if desired) but generally not by end-station hosts. It is a read-write table. The values proposed below are defaults and can be overridden by management control so long as all switches agree to some extent (the required level of agreement requires further analysis).
为了简化更改映射的任务，此映射表由*交换机*（以及路由器，如果需要）持有，但通常不由终端站主机持有。它是一个读写表。以下建议的值是默认值，只要所有开关在某种程度上一致（所需的一致性水平需要进一步分析），管理控制就可以覆盖这些值。
In future networks this mapping table might be adjusted dynamically and without human intervention. It is possible that some form of network-wide lookup service could be implemented that serviced requests from clients e.g., traffic_class = getQoSbyName("H.323 video") and notified switches of what traffic categories they were likely to encounter and how to allocate those requests into traffic classes. Alternatively, the network's admission control mechanisms might directly adjust the mapping table to maximize the utilization of network resources. Such mechanisms are for further study.
在未来的网络中，此映射表可能会在无需人工干预的情况下动态调整。有可能实现某种形式的网络范围查找服务，为来自客户端的请求提供服务，例如，traffic_class=getQoSbyName（“H.323视频”），并通知交换机可能遇到的流量类别以及如何将这些请求分配到流量类别。或者，网络的接纳控制机制可以直接调整映射表以最大限度地利用网络资源。这些机制有待进一步研究。
The delay bounds numbers proposed in Table 1 are for per-Bandwidth Allocator element delay targets and are derived from a subjective analysis of the needs of typical delay-sensitive applications e.g., voice, video. See Annex H of [802.1D] for further discussion of the selection of these values. Although these values appear to address the needs of current video and voice technology, it should be noted that there is no requirement to adhere to these values and no dependence of IEEE 802.1 on these values.
表1中提出的延迟边界数是针对每个带宽分配器元件的延迟目标，并根据对典型延迟敏感应用（如语音、视频）需求的主观分析得出。有关这些值选择的进一步讨论，请参见[802.1D]的附录H。尽管这些值似乎满足了当前视频和语音技术的需求，但应注意的是，不需要遵守这些值，IEEE 802.1也不依赖这些值。
user_priority Service
用户优先服务
0 Default, assumed to be Best Effort 1 reserved, "less than" Best Effort 2 reserved 3 reserved 4 Delay Sensitive, no bound 5 Delay Sensitive, 100ms bound 6 Delay Sensitive, 10ms bound 7 Network Control
默认值为0，假设最大努力1保留，“小于”最大努力2保留3保留4延迟敏感，无限制5延迟敏感，100ms限制6延迟敏感，10ms限制7网络控制
Table 1 - Example user_priority to service mappings
表1-用户优先级到服务映射示例
Note: These mappings are believed to be useful defaults but further implementation and usage experience is required. The mappings may be refined in future editions of this document.
注意：这些映射被认为是有用的默认值，但需要进一步的实现和使用经验。这些映射可能会在本文档的未来版本中进行细化。
With this example set of mappings, delay-sensitive, admission controlled traffic flows are mapped to user_priority values in ascending order of their delay bound requirement. Note that the bounds are targets only - see [IS802FRAME] for a discussion of the effects of other non-conformant flows on delay bounds of other flows. Only by applying admission control to higher-priority classes can any promises be made to lower-priority classes.
通过这组映射示例，延迟敏感的、准入控制的业务流按照其延迟限制需求的升序映射到用户_优先级值。请注意，边界仅为目标-有关其他非一致流对其他流延迟边界的影响的讨论，请参见[IS802FRAME]。只有对高优先级的类应用准入控制，才能对低优先级的类做出任何承诺。
This set of mappings also leaves several classes as reserved for future definition.
这组映射还保留了几个类供将来定义。
Note: this mapping does not dictate what mechanisms or algorithms a network element (e.g., an Ethernet switch) must perform to implement these mappings: this is an implementation choice and does not matter so long as the requirements for the particular service model are met.
注意：此映射并不规定网元（如以太网交换机）必须执行哪些机制或算法来实现这些映射：这是一种实现选择，只要满足特定服务模型的要求，就无所谓。
Note: these mappings apply primarily to networks constructed from devices that implement the priority-scheduling behavior defined as the default in 802.1D. Some devices may implement more complex scheduling behaviors not based only on priority. In that circumstance these mappings might still be used, but other, more
注意：这些映射主要适用于由实现802.1D中默认优先级调度行为的设备构建的网络。一些设备可能实现更复杂的调度行为，而不仅仅是基于优先级。在这种情况下，这些映射可能仍然会被使用，但其他映射可能会更多
specialized mappings may be more appropriate.
专用映射可能更合适。
The recommendation of classes 4, 5 and 6 for Delay Sensitive, Admission Controlled flows is somewhat arbitrary; any classes with priorities greater than that assigned to Best Effort can be used. Those proposed here have the advantage that, for transit through 802.1D switches with only two-level strict priority queuing, all delay-sensitive traffic gets "high priority" treatment (the 802.1D default split is 0-3 and 4-7 for a device with 2 queues).
对于延迟敏感的准入控制流，建议使用4、5和6类，这有点随意；可以使用优先级大于指定给Best Effort的任何类。此处提出的方案的优点是，对于仅具有两级严格优先级队列的802.1D交换机，所有对延迟敏感的流量都会得到“高优先级”处理（对于具有两个队列的设备，802.1D默认拆分为0-3和4-7）。
The choice of the delay bound targets is tuned to an average expected application mix, and might be retuned by a network manager facing a widely different mix of user needs. The choice is potentially very significant: wise choice can lead to a much more efficient allocation of resources as well as greater (though still not very good) isolation between flows.
延迟限制目标的选择被调整为平均预期的应用程序组合，并且可能会由网络管理器重新调整，以满足不同的用户需求组合。这一选择可能非常重要：明智的选择可以导致更有效的资源分配以及流之间更大的（尽管仍然不是很好）隔离。
Placing Network Control traffic at class 7 is necessary to protect important traffic such as route updates and network management. Unfortunately, placing this traffic higher in the user_priority ordering causes it to have a direct effect on the ability of devices to provide assurances to QoS controlled application traffic. Therefore, an estimate of the amount of Network Control traffic must be made by any device that is performing admission control (e.g., SBMs). This would be in terms of the parameters that are normally taken into account by the admission control algorithm. This estimate should be used in the admission control decisions for the lower classes (the estimate is likely to be a configuration parameter of SBMs).
将网络控制流量设置为7级是保护重要流量（如路由更新和网络管理）所必需的。不幸的是，将此流量置于用户_优先级顺序的更高位置会直接影响设备为QoS控制的应用程序流量提供保证的能力。因此，必须由执行接纳控制的任何设备（例如，SBMs）对网络控制业务量进行估计。这是根据准入控制算法通常考虑的参数。该估计值应用于下层阶级的准入控制决策（该估计值可能是SBMs的配置参数）。
A traffic class such as class 1 for "less than best effort" might be useful for devices that wish to dynamically "penalty tag" all of the data of flows that are presently exceeding their allocation or Tspec. This provides a way to isolate flows that are exceeding their service limits from flows that are not, to avoid reducing the QoS delivered to flows that are within their contract. Data from such tagged flows might also be preferentially discarded by an overloaded downstream device.
对于希望动态地“惩罚标记”当前超过其分配或Tspec的流的所有数据的设备来说，诸如“小于最大努力”的类1之类的流量类可能是有用的。这提供了一种将超出其服务限制的流与未超出其服务限制的流隔离开来的方法，以避免降低交付到其合约内的流的QoS。来自此类标记流的数据也可能被过载的下游设备优先丢弃。
A somewhat simpler approach would be to tag only the portion of a flow's packets that actually exceed the Tspec at any given instant as low priority. However, it is often considered to be a bad idea to treat flows in this way as it will likely cause significant re-ordering of the flow's packets, which is not desirable. Note that the default 802.1D treatment of user_priorities 1 and 2 is "less than" the default class 0.
一种更简单的方法是仅将流数据包中在任何给定时刻实际超过Tspec的部分标记为低优先级。然而，以这种方式处理流通常被认为是一个坏主意，因为它可能会导致流的数据包的显著重新排序，这是不可取的。请注意，用户优先级1和2的默认802.1D处理“小于”默认类别0。
4. Computation of integrated services characterization parameters by IEEE 802 devices
4. ieee802设备综合业务特征参数的计算
The integrated service model requires that each network element that supports integrated services compute and make available certain "characterization parameters" describing the element's behavior. These parameters may be either generally applicable or specific to a particular QoS control service. These parameters may be computed by calculation, measurement, or estimation. When a network element cannot compute its own parameters (for example, a simple link), we assume that the device sending onto or receiving data from the link will compute the link's parameters as well as it's own. The accuracy of calculation of these parameters may not be very critical; in some cases loose estimates are all that is required to provide a useful service. This is important in the IEEE 802 case, where it will be virtually impossible to compute parameters accurately for certain topologies and switch technologies. Indeed, it is an assumption of the use of this model by relatively simple switches (see [IS802FRAME] for a discussion of the different types of switch functionality that might be expected) that they merely provide values to describe the device and admit flows conservatively. The discussion below presents a general outline for the computation of these parameters, and points out some cases where the parameters must be computed accurately. Further specification of how to export these parameters is for further study.
集成服务模型要求支持集成服务的每个网元计算并提供描述元素行为的特定“特征参数”。这些参数可以是一般适用的，也可以是特定于特定QoS控制服务的。这些参数可以通过计算、测量或估计来计算。当网元无法计算其自身的参数（例如，简单链路）时，我们假设发送到链路或从链路接收数据的设备将计算链路的参数以及自身的参数。这些参数的计算精度可能不是很关键；在某些情况下，提供有用的服务所需的只是粗略的估计。这在IEEE 802的情况下很重要，在这种情况下，几乎不可能精确计算某些拓扑和交换机技术的参数。事实上，通过相对简单的交换机（参见[IS802FRAME]了解可能预期的不同类型的交换机功能的讨论）使用该模型的一个假设是，它们仅提供值来描述设备并保守地允许流。下面的讨论给出了这些参数计算的一般概述，并指出了必须准确计算参数的一些情况。如何导出这些参数的进一步说明有待进一步研究。
There are some general parameters [GENCHAR] that a device will need to use and/or supply for all service types:
设备需要为所有服务类型使用和/或提供一些通用参数[GENCHAR]：
* Ingress link
* 入口链路
* Egress links and their MTUs, framing overheads and minimum packet sizes (see media-specific information presented above).
* 出口链路及其MTU、帧开销和最小数据包大小（请参阅上述媒体特定信息）。
* Available path bandwidth: updated hop-by-hop by any device along the path of the flow.
* 可用路径带宽：由流路径上的任何设备逐跳更新。
* Minimum latency
* 最小延迟
Of these parameters, the MTU and minimum packet size information must be reported accurately. Also, the "break bits" must be set correctly, both the overall bit that indicates the existence of QoS control support and the individual bits that specify support for a particular scheduling service. The available bandwidth should be reported as accurately as possible, but very loose estimates are acceptable. The minimum latency parameter should be determined and reported as
在这些参数中，必须准确报告MTU和最小数据包大小信息。此外，必须正确设置“中断位”，包括指示存在QoS控制支持的总体位和指定特定调度服务支持的单个位。应尽可能准确地报告可用带宽，但可以接受非常松散的估计。应确定最小延迟参数，并将其报告为
accurately as possible if the element offers Guaranteed service, but may be loosely estimated or reported as zero if the element offers only Controlled-Load service.
如果元件提供有保证的服务，则尽可能准确，但如果元件仅提供受控负载服务，则可能粗略估计或报告为零。
A network element supporting the Guaranteed Service [GS] must be able to determine the following parameters:
支持保证服务[GS]的网元必须能够确定以下参数：
* Constant delay bound through this device (in addition to any value provided by "minimum latency" above) and up to the receiver at the next network element for the packets of this flow if it were to be admitted. This includes any access latency bound to the outgoing link as well as propagation delay across that link. This value is advertised as the 'C' parameter of the Guaranteed Service.
* 通过该设备（除上述“最小延迟”提供的任何值外）并在下一网络元件处向接收器发送该流数据包（如果要接收）的恒定延迟。这包括绑定到传出链路的任何访问延迟以及该链路上的传播延迟。此值作为保证服务的“C”参数公布。
* Rate-proportional delay bound through this device and up to the receiver at the next network element for the packets of this flow if it were to be admitted. This value is advertised as the 'D' parameter of the Guaranteed Service.
* 速率比例延迟通过该设备限制，并在下一个网元上到达该流数据包的接收器（如果要接收）。此值作为保证服务的“D”参数公布。
* Receive resources that would need to be associated with this flow (e.g., buffering, bandwidth) if it were to be admitted and not suffer packet loss if it kept within its supplied Tspec/Rspec. These values are used by the admission control algorithm to decide whether a new flow can be accepted by the device.
* 接收需要与该流关联的资源（例如，缓冲、带宽），如果该流要被接纳，并且如果它保持在其提供的Tspec/Rspec内，则不会遭受数据包丢失。准入控制算法使用这些值来决定设备是否可以接受新流量。
* Transmit resources that would need to be associated with this flow (e.g., buffering, bandwidth, constant- and rate-proportional delay bounds) if it were to be admitted. These values are used by the admission control algorithm to decide whether a new flow can be accepted by the device.
* 传输需要与该流相关联的资源（例如，缓冲、带宽、恒定速率和比例延迟边界），如果允许的话。准入控制算法使用这些值来决定设备是否可以接受新流量。
The exported characterization parameters for this service should be reported as accurately as possible. If estimations or approximations are used, they should err in whatever direction causes the user to receive better performance than requested. For example, the C and D error terms should overestimate delay, rather than underestimate it.
应尽可能准确地报告此服务的导出表征参数。如果使用估计值或近似值，则它们在任何方向上都会出错，从而导致用户获得比请求的更好的性能。例如，C和D错误项应该高估延迟，而不是低估延迟。
A network element implementing the Controlled Load service [CL] must be able to determine the following:
实现受控负载服务[CL]的网元必须能够确定以下各项：
* Receive resources that would need to be associated with this flow (e.g., buffering) if it were to be admitted. These values are used by the admission control algorithm to decide whether a new flow can be accepted by the device.
* 接收需要与此流关联的资源（例如，缓冲），如果要允许它。准入控制算法使用这些值来决定设备是否可以接受新流量。
* Transmit resources that would need to be associated with this flow (e.g., buffering) if it were to be admitted. These values are used by the admission control algorithm to decide whether a new flow can be accepted by the device.
* 传输需要与此流关联的资源（例如，缓冲），如果要允许它。准入控制算法使用这些值来决定设备是否可以接受新流量。
The Controlled Load service does not export any service-specific characterization parameters. Internal resource allocation estimates should ensure that the service quality remains high when considering the statistical aggregation of Controlled Load flows into 802 traffic classes.
受控负载服务不会导出任何特定于服务的特征参数。内部资源分配估计应确保在考虑将受控负载流统计聚合到802流量类别时，服务质量保持较高。
For a network element that implements only best effort service there are no explicit parameters that need to be characterized. Note that an integrated services aware network element that implements only best effort service will set the "break bit" described in [RSVPINTSERV].
对于只实现尽力而为服务的网元，没有需要描述的显式参数。请注意，仅实现尽力而为服务的集成服务感知网元将设置[RSVPINTSERV]中所述的“中断位”。
Where reservations that use the SBM protocol's TCLASS object [SBM] need to be merged, an algorithm needs to be defined that is consistent with the mappings to individual user_priority values in use in the Layer-2 cloud. A merged reservation must receive at least as good a service as the best of the component reservations.
如果需要合并使用SBM协议的TCLASS对象[SBM]的预订，则需要定义一种算法，该算法与第二层云中使用的单个用户_优先级值的映射一致。合并的预订必须至少收到与最佳组件预订相同的服务。
There is no single merging rule that can prevent all of the following side-effects:
没有单一的合并规则可以防止以下所有副作用：
* If a merger were to demote the existing branch of the flow into a higher-delay traffic class then this is a denial of service to the existing flow which would likely receive worse service than before.
* 如果合并将流的现有分支降级为更高的延迟流量类别，则这是对现有流的拒绝服务，可能会收到比以前更差的服务。
* If a merger were to promote the existing branch of the flow into a new, lower-delay, traffic class, this might then suffer either admission control failures or may cost more in some sense than the already-admitted flow. This can also be considered as a denial-of-service attack.
* 如果合并将现有的流量分支提升到一个新的、较低延迟的流量类别，那么这可能会导致接纳控制失败，或者在某种意义上比已经接纳的流量成本更高。这也可以被视为拒绝服务攻击。
* Promotion of the new branch may lead to rejection of the request because it has been re-assigned to a traffic class that has not enough resources to accommodate it.
* 提升新分支可能会导致拒绝请求，因为它已被重新分配给没有足够资源容纳它的流量类。
Therefore, such a merger is declared to be illegal and the usual SBM admission control failure rules are applied. Traffic class selection is performed based on the TSpec information. When the first RESV for
因此，此类合并被宣布为非法，并适用通常的SBM准入控制失败规则。基于TSpec信息执行业务类别选择。当第一个RESV为
a flow arrives, a traffic class is chosen based on the request, an SBM TCLASS object is inserted into the message and admission control for that traffic class is done by the SBM. Reservation succeeds or fails as usual.
流到达时，根据请求选择流量类别，将SBM TCLASS对象插入消息中，并由SBM对该流量类别进行准入控制。预订照常成功或失败。
When a second RESV for the same flow arrives at a different egress point of the Layer-2 cloud the process starts to repeat. Eventually the SBM-augmented RESV may hit a switch with an existing reservation in place for the flow i.e., an L2 branch point for the flow. If so, the traffic class chosen for the second reservation is checked against the first. If they are the same, the RESV requests are merged and passed on towards the sender(s).
当相同流的第二个RESV到达第二层云的不同出口点时，该过程开始重复。最终，SBM增强的RESV可能会碰到一个交换机，该交换机具有流的现有保留，即流的L2分支点。如果是这样，将对照第一个预订检查为第二个预订选择的流量类别。如果它们相同，则合并RESV请求并将其传递给发送方。
If the second TCLASS would have been different, an RSVP/SBM ResvErr error is returned to the Layer-3 device that launched the second RESV request into the Layer-2 cloud. This device will then pass on the ResvErr to the original requester according to RSVP rules. Detailed processing rules are specified in [SBM].
如果第二个TCLASS不同，则向向第二层云中发出第二个RESV请求的第三层设备返回RSVP/SBM ResvErr错误。然后，该设备将根据RSVP规则将ResvErr传递给原始请求者。[SBM]中规定了详细的处理规则。
Switches using layer-2-only standards (e.g., 802.1D-1990, 802.1D-1998) need to inter-operate with routers and layer-3 switches. Wide deployment of such 802.1D-1998 switches will occur in a number of roles in the network: "desktop switches" provide dedicated 10/100 Mbps links to end stations and high speed core switches often act as central campus switching points for layer-3 devices. Layer-2 devices will have to operate in all of the following scenarios:
使用仅第2层标准（例如802.1D-1990、802.1D-1998）的交换机需要与路由器和第3层交换机交互操作。这种802.1D-1998交换机将在网络中的许多角色中广泛部署：“桌面交换机”提供到终端站的专用10/100 Mbps链路，高速核心交换机通常充当第3层设备的中心校园交换点。第2层设备必须在以下所有情况下运行：
* every device along a network path is layer-3 capable and intrusive into the full data stream
* 网络路径上的每个设备都具有第3层功能，可以侵入整个数据流
* only the edge devices are pure layer-2
* 只有边缘设备是纯第2层
* every alternate device lacks layer-3 functionality
* 每个备用设备都缺少第三层功能
* most devices lack layer-3 functionality except for some key control points such as router firewalls, for example.
* 除一些关键控制点（例如路由器防火墙）外，大多数设备缺乏第三层功能。
Where int-serv flows pass through equipment which does not support Integrated Services or 802.1D traffic management and which places all packets through the same queuing and overload-dropping paths, it is obvious that some of a flow's desired service parameters become more difficult to support. In particular, the two integrated service classes studied here, Controlled Load and Guaranteed Service, both assume that flows will be policed and kept "insulated" from misbehaving other flows or from best effort traffic during their passage through the network. This cannot be
当int-serv流通过不支持集成服务或802.1D流量管理且将所有数据包置于相同的排队和过载丢弃路径的设备时，显然流的一些期望服务参数变得更难支持。特别是，这里研究的两个集成服务类，控制负载和保证服务，都假设在流通过网络的过程中，将对流进行监控，并使其与行为不端的其他流或尽力而为的流量“隔离”。这不可能
done within an IEEE 802 network using devices with the default user_priority function; in this case policing must be approximated at the network edges.
在IEEE 802网络内使用具有默认用户优先级功能的设备完成；在这种情况下，必须在网络边缘进行近似的监控。
In addition, in order to provide a Guaranteed Service, *all* switching elements along the path must participate in special treatment for packets in such flows: where there is a "break" in guaranteed service, all bets are off. Thus, a network path that includes even a single switch transmitting onto a shared or half-duplex LAN segment is unlikely to be able to provide a very good approximation to Guaranteed Service. For Controlled Load service, the requirements on the switches and link types are less stringent although it is still necessary to provide differential queuing and buffering in switches for CL flows over best effort in order to approximate CL service. Note that users receive indication of such breaks in the path through the "break bits" described in y [RSVPINTSERV]. These bits must be correctly set when IEEE 802 devices that cannot provide a specific service exist in a network.
此外，为了提供保证服务，路径上的*所有*交换元件必须参与对此类流中的数据包的特殊处理：在保证服务中出现“中断”的情况下，所有下注都被取消。因此，即使包括单个交换机传输到共享或半双工LAN段的网络路径也不可能提供非常好的近似保证服务。对于受控负载服务，对交换机和链路类型的要求不那么严格，尽管仍有必要在交换机中提供差分排队和缓冲，以便尽最大努力实现CL服务。请注意，用户通过y[RSVPINTSERV]中描述的“中断位”在路径中接收此类中断的指示。当网络中存在无法提供特定服务的IEEE 802设备时，必须正确设置这些位。
Other approaches might be to pass more information between switches about the capabilities of their neighbours and to route around non-QoS-capable switches: such methods are for further study. And of course the easiest solution of all is to upgrade links and switches to higher capacities.
其他方法可能是在交换机之间传递更多关于其邻居的能力的信息，并围绕不具备QoS能力的交换机进行路由：这些方法有待进一步研究。当然，最简单的解决方案是将链路和交换机升级到更高的容量。
[802.1D-ORIG] "MAC Bridges", ISO/IEC 10038, ANSI/IEEE Std 802.1D-1993
[802.1D-ORIG]“MAC网桥”，ISO/IEC 10038，ANSI/IEEE标准802.1D-1993
[802.1D] "Information technology - Telecommunications and
information exchange between systems - Local and
metropolitan area networks - Common specifications -
Part 3: Media Access Control (MAC) Bridges: Revision.
This is a revision of ISO/IEC 10038: 1993, 802.1j-1992
and 802.6k-1992. It incorporates P802.11c, P802.1p and
P802.12e." ISO/IEC 15802-3:1998"
[802.1D] "Information technology - Telecommunications and
information exchange between systems - Local and
metropolitan area networks - Common specifications -
Part 3: Media Access Control (MAC) Bridges: Revision.
This is a revision of ISO/IEC 10038: 1993, 802.1j-1992
and 802.6k-1992. It incorporates P802.11c, P802.1p and
P802.12e." ISO/IEC 15802-3:1998"
[INTSERV] Braden, R., Clark, D. and S. Shenker, "Integrated Services in the Internet Architecture: an Overview", RFC 1633, June 1994.
[INTSERV]Braden，R.，Clark，D.和S.Shenker，“互联网体系结构中的综合服务：概述”，RFC 16331994年6月。
[RSVP] Braden, R., Zhang, L., Berson, S., Herzog, S. and S. Jamin, "Resource Reservation Protocol (RSVP) - Version 1 Functional Specification", RFC 2205, September 1997.
[RSVP]Braden，R.，Zhang，L.，Berson，S.，Herzog，S.和S.Jamin，“资源预留协议（RSVP）-第1版功能规范”，RFC 22052997年9月。
[CL] Wroclawski, J., "Specification of the Controlled-Load Network Element Service", RFC 2211, September 1997.
[CL]Wroclawski，J.“受控负荷网元服务规范”，RFC 2211，1997年9月。
[GS] Schenker, S., Partridge, C. and R. Guerin, "Specification of Guaranteed Quality of Service", RFC 2212 September 1997.
[GS]Schenker，S.，Partridge，C.和R.Guerin，“保证服务质量规范”，RFC 2212 1997年9月。
[802.1Q] ANSI/IEEE Standard 802.1Q-1998, "IEEE Standards for Local and Metropolitan Area Networks: Virtual Bridged Local Area Networks", 1998.
[802.1Q]ANSI/IEEE标准802.1Q-1998，“局域网和城域网的IEEE标准：虚拟桥接局域网”，1998年。
[GENCHAR] Shenker, S., and J. Wroclawski, "General Characterization Parameters for Integrated Service Network Elements", RFC 2215, September 1997.
[GENCHAR]Shenker，S.和J.Wroclawski，“综合业务网元的一般特征参数”，RFC 2215，1997年9月。
[IS802FRAME] Ghanwani, A., Pace, W., Srinivasan, V., Smith, A. and M. Seaman, "A Framework for Providing Integrated Services Over Shared and Switched LAN Technologies", RFC 2816, May 2000.
[IS802FRAME]Ghanwani，A.，Pace，W.，Srinivasan，V.，Smith，A.和M.Seaman，“通过共享和交换LAN技术提供综合服务的框架”，RFC 28162000年5月。
[SBM] Yavatkar, R., Hoffman, D., Bernet, Y., Baker, F. and M. Speer, "SBM (Subnet Bandwidth Manager): A Protocol for Admission Control over IEEE 802-style Networks", RFC 2814, May 2000.
[SBM]Yavatkar，R.，Hoffman，D.，Bernet，Y.，Baker，F.和M.Speer，“SBM（子网带宽管理器）：IEEE 802风格网络上的准入控制协议”，RFC 2814，2000年5月。
[RSVPINTSERV] Wroclawski, J., "The use of RSVP with IETF Integrated Services", RFC 2210, September 1997.
[RSVPINTSERV]Wroclawski，J.，“RSVP与IETF综合服务的使用”，RFC 2210，1997年9月。
[PROCESS] Bradner, S., "The Internet Standards Process -- Revision 3", BCP 9, RFC 2026, October 1996.
[过程]Bradner，S.，“互联网标准过程——第3版”，BCP 9，RFC 2026，1996年10月。
Any use of QoS requires examination of security considerations because it leaves the possibility open for denial of service or theft of service attacks. This document introduces no new security issues on top of those discussed in the companion ISSLL documents [IS802FRAME] and [SBM]. Any use of these service mappings assumes that all requests for service are authenticated appropriately.
QoS的任何使用都需要检查安全注意事项，因为它会留下拒绝服务或窃取服务攻击的可能性。本文档除了在配套ISSL文档[IS802FRAME]和[SBM]中讨论的安全问题外，没有引入任何新的安全问题。这些服务映射的任何使用都假定所有服务请求都经过适当的身份验证。
This document draws heavily on the work of the ISSLL WG of the IETF and the IEEE P802.1 Interworking Task Group.
本文件大量借鉴了IETF的ISSLL工作组和IEEE P802.1互通工作组的工作。
Mick Seaman Telseon 480 S. California Ave Palo Alto, CA 94306 USA
美国加利福尼亚州帕洛阿尔托市南加利福尼亚大道480号米克·希曼电信公司，邮编94306
Email: mick@telseon.com
Email: mick@telseon.com
Andrew Smith Extreme Networks 3585 Monroe St. Santa Clara, CA 95051 USA
安德鲁·史密斯极限网络美国加利福尼亚州圣克拉拉门罗街3585号，邮编95051
Phone: +1 408 579 2821
EMail: andrew@extremenetworks.com
Phone: +1 408 579 2821
EMail: andrew@extremenetworks.com
Eric Crawley Unisphere Solutions 5 Carlisle Rd. Westford, MA 01886
马萨诸塞州韦斯特福德卡莱尔路5号Eric Crawley Unisphere Solutions 01886
Phone: +1 978 692 1999
Email: esc@unispheresolutions.com
Phone: +1 978 692 1999
Email: esc@unispheresolutions.com
John Wroclawski MIT Laboratory for Computer Science 545 Technology Sq. Cambridge, MA 02139 USA
约翰·沃克罗夫斯基麻省理工学院计算机科学实验室545技术Sq.剑桥，马萨诸塞州02139
Phone: +1 617 253 7885
EMail: jtw@lcs.mit.edu
Phone: +1 617 253 7885
EMail: jtw@lcs.mit.edu
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确认
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