Network Working Group D. Papadimitriou
Request for Comments: 4139 Alcatel
Category: Informational J. Drake
Boeing
J. Ash
ATT
A. Farrel
Old Dog Consulting
L. Ong
Ciena
July 2005
Network Working Group D. Papadimitriou
Request for Comments: 4139 Alcatel
Category: Informational J. Drake
Boeing
J. Ash
ATT
A. Farrel
Old Dog Consulting
L. Ong
Ciena
July 2005
Requirements for Generalized MPLS (GMPLS) Signaling Usage and Extensions for Automatically Switched Optical Network (ASON)
自动交换光网络（ASON）的通用MPLS（GMPLS）信令使用和扩展要求
Status of This Memo
关于下段备忘
This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited.
本备忘录为互联网社区提供信息。它没有规定任何类型的互联网标准。本备忘录的分发不受限制。
Copyright Notice
版权公告
Copyright (C) The Internet Society (2005).
版权所有（C）互联网协会（2005年）。
Abstract
摘要
The Generalized Multi-Protocol Label Switching (GMPLS) suite of protocols has been defined to control different switching technologies and different applications. These include support for requesting Time Division Multiplexing (TDM) connections, including Synchronous Optical Network (SONET)/Synchronous Digital Hierarchy (SDH) and Optical Transport Networks (OTNs).
广义多协议标签交换（GMPLS）协议套件被定义用于控制不同的交换技术和不同的应用。其中包括支持请求时分复用（TDM）连接，包括同步光网络（SONET）/同步数字体系（SDH）和光传输网络（OTN）。
This document concentrates on the signaling aspects of the GMPLS suite of protocols. It identifies the features to be covered by the GMPLS signaling protocol to support the capabilities of an Automatically Switched Optical Network (ASON). This document provides a problem statement and additional requirements for the GMPLS signaling protocol to support the ASON functionality.
本文档集中于GMPLS协议套件的信令方面。它确定了GMPLS信令协议所涵盖的功能，以支持自动交换光网络（ASON）的功能。本文档提供了GMPLS信令协议的问题陈述和附加要求，以支持ASON功能。
The Generalized Multi-Protocol Label Switching (GMPLS) suite of protocol specifications provides support for controlling different switching technologies and different applications. These include support for requesting Time Division Multiplexing (TDM) connections, including Synchronous Optical Network (SONET)/Synchronous Digital Hierarchy (SDH) (see [ANSI-T1.105] and [ITU-T-G.707], respectively), and Optical Transport Networks (see [ITU-T-G.709]). In addition, there are certain capabilities needed to support Automatically Switched Optical Networks control planes (their architecture is defined in [ITU-T-G.8080]). These include generic capabilities such as call and connection separation, along with more specific capabilities such as support of soft permanent connections.
通用多协议标签交换（GMPLS）协议规范套件为控制不同的交换技术和不同的应用提供了支持。其中包括对请求时分复用（TDM）连接的支持，包括同步光网络（SONET）/同步数字体系（SDH）（分别参见[ANSI-T1.105]和[ITU-T-G.707]）和光传输网络（参见[ITU-T-G.709]）。此外，还需要某些功能来支持自动交换光网络控制平面（其体系结构在[ITU-T-G.8080]中定义）。这些功能包括通用功能，如呼叫和连接分离，以及更具体的功能，如支持软永久连接。
This document concentrates on requirements related to the signaling aspects of the GMPLS suite of protocols. It discusses the functional requirements required to support Automatically Switched Optical Networks that may lead to additional extensions to GMPLS signaling (see [RFC3471] and [RFC3473]) to support these capabilities. In addition to ASON signaling requirements, this document includes GMPLS signaling requirements that pertain to backward compatibility (Section 5). A terminology section is provided in the Appendix.
本文件集中于与GMPLS协议套件的信令方面相关的要求。它讨论了支持自动交换光网络所需的功能要求，这可能导致GMPLS信令的额外扩展（参见[RFC3471]和[RFC3473]），以支持这些功能。除ASON信令要求外，本文件还包括与向后兼容性有关的GMPLS信令要求（第5节）。附录中提供了术语部分。
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].
本文件中的关键词“必须”、“不得”、“必需”、“应”、“不应”、“应”、“不应”、“建议”、“可”和“可选”应按照[RFC2119]中所述进行解释。
While [RFC2119] describes interpretations of these key words in terms of protocol specifications and implementations, they are used in this document to describe design requirements for protocol extensions.
虽然[RFC2119]从协议规范和实现的角度描述了这些关键词的解释，但在本文档中，它们用于描述协议扩展的设计要求。
The Automatically Switched Optical Network (ASON) architecture describes the application of an automated control plane for supporting both call and connection management services (for a detailed description see [ITU-T-G.8080]). The ASON architecture describes a reference architecture, (i.e., it describes functional components, abstract interfaces, and interactions).
自动交换光网络（ASON）体系结构描述了支持呼叫和连接管理服务的自动控制平面的应用（详细描述见[ITU-T-G.8080]）。ASON架构描述了参考架构（即，它描述了功能组件、抽象接口和交互）。
The ASON model distinguishes reference points (representing points of information exchange) defined (1) between a user (service requester) and a service provider control domain, a.k.a. user-network interface (UNI), (2) between control domains, a.k.a. external network-network interface (E-NNI), and, (3) within a control domain, a.k.a. internal
ASON模型区分了（1）用户（服务请求者）和服务提供者控制域（也称为用户网络接口（UNI））之间定义的参考点（表示信息交换点），（2）控制域（也称为外部网络接口（E-NNI））之间定义的参考点，以及（3）控制域（也称为内部网络接口）
network-network interface (I-NNI). The I-NNI and E-NNI interfaces are between protocol controllers, and may or may not use transport plane (physical) links. It must not be assumed that there is a one-to-one relationship between control plane interfaces and transport plane (physical) links, control plane entities and transport plane entities, or control plane identifiers for transport plane resources.
网络接口（I-NNI）。I-NNI和E-NNI接口位于协议控制器之间，可以使用也可以不使用传输平面（物理）链路。不得假设控制平面接口和传输平面（物理）链路、控制平面实体和传输平面实体或传输平面资源的控制平面标识符之间存在一对一的关系。
This document describes requirements related to the use of GMPLS signaling (in particular, [RFC3471] and [RFC3473]) to provide call and connection management (see [ITU-T-G.7713]). The functionality to be supported includes:
本文件描述了使用GMPLS信令（特别是[RFC3471]和[RFC3473]）提供呼叫和连接管理的相关要求（见[ITU-T-G.7713]）。要支持的功能包括：
(a) soft permanent connection capability (b) call and connection separation (c) call segments (d) extended restart capabilities during control plane failures (e) extended label association (f) crankback capability (g) additional error cases
(a) 软永久连接能力（b）呼叫和连接分离（c）呼叫段（d）控制平面故障期间的扩展重启能力（e）扩展标签关联（f）回退能力（g）其他错误情况
The following sections detail the signaling protocol requirements for GMPLS to support the ASON functions listed in Section 3. ASON defines a reference model and functions (information elements) to enable end-to-end call and connection support by a protocol across the respective interfaces, regardless of the particular choice of protocol(s) used in a network. ASON does not restrict the use of other protocols or the protocol-specific messages used to support the ASON functions. Therefore, the support of these ASON functions by a protocol shall not be restricted by (i.e., must be strictly independent of and agnostic to) any particular choice of UNI, I-NNI, or E-NNI used elsewhere in the network. To allow for interworking between different protocol implementations, [ITU-T-G.7713] recognizes that an interworking function may be needed.
以下各节详细说明了GMPLS支持第3节所列ASON功能的信令协议要求。ASON定义了一个参考模型和功能（信息元素），以通过协议在各个接口上实现端到端呼叫和连接支持，而不考虑网络中使用的协议的特定选择。ASON不限制用于支持ASON功能的其他协议或协议特定消息的使用。因此，协议对这些ASON功能的支持不应受到（即，必须严格独立于和不可知于）网络中其他地方使用的UNI、i-NNI或e-NNI的任何特定选择的限制。为了允许不同协议实施之间的互通，[ITU-T-G.7713]认识到可能需要互通功能。
In support of the G.8080 end-to-end call model across different control domains, end-to-end signaling should be facilitated regardless of the administrative boundaries, protocols within the network, or the method of realization of connections within any part of the network. This implies the need for a clear mapping of ASON signaling requests between GMPLS control domains and non-GMPLS control domains. This document provides signaling requirements for G.8080 distributed call and connection management based on GMPLS, within a GMPLS based control domain (I-NNI), and between GMPLS based control domains (E-NNI). It does not restrict use of other (non GMPLS) protocols to be used within a control domain or as an E-NNI or UNI. Interworking aspects related to the use of non-GMPLS protocols,
为了支持G.8080跨不同控制域的端到端呼叫模型，应促进端到端信令，而不考虑管理边界、网络内的协议或网络任何部分内连接的实现方法。这意味着需要在GMPLS控制域和非GMPLS控制域之间清晰地映射ASON信令请求。本文件提供了基于GMPLS、基于GMPLS的控制域（I-NNI）内以及基于GMPLS的控制域（E-NNI）之间的G.8080分布式呼叫和连接管理的信令要求。它不限制在控制域内或作为E-NNI或UNI使用其他（非GMPLS）协议。与使用非GMPLS协议相关的互通方面，
such as UNI, E-NNI, or I-NNI -- including mapping of non-GMPLS protocol signaling requests to corresponding ASON signaling functionality and support of non-GMPLS address formats -- is not within the scope of the GMPLS signaling protocol. Interworking aspects are implementation-specific and strictly under the responsibility of the interworking function and, thus, outside the scope of this document.
例如UNI、E-NNI或I-NNI——包括将非GMPLS协议信令请求映射到相应的ASON信令功能和支持非GMPLS地址格式——不在GMPLS信令协议的范围内。互通方面是具体实施的，严格由互通职能部门负责，因此不在本文件范围内。
By definition, any User-Network Interface (UNI) that is compliant with [RFC3473] (e.g., [GMPLS-OVERLAY] and [GMPLS-VPN]) is considered to be included within the GMPLS suite of protocols and MUST be supported by the ASON GMPLS signaling functionality.
根据定义，任何符合[RFC3473]（例如[GMPLS-OVERLAY]和[GMPLS-VPN]）的用户网络接口（UNI）都被视为包含在GMPLS协议套件中，并且必须由ASON GMPLS信令功能支持。
Compatibility aspects of non-GMPLS systems (nodes) within a GMPLS control domain (i.e., the support of GMPLS systems and other systems that utilize other signaling protocols or some that may not support any signaling protocols) is described. For example, Section 4.5, 'Support for Extended Label Association', covers the requirements for when a non-GMPLS capable sub-network is introduced or when nodes do not support any signaling protocols.
描述了GMPLS控制域内非GMPLS系统（节点）的兼容性方面（即，对GMPLS系统和利用其他信令协议的其他系统或可能不支持任何信令协议的一些系统的支持）。例如，第4.5节“扩展标签关联的支持”涵盖了引入不支持GMPLS的子网或节点不支持任何信令协议时的要求。
A Soft Permanent Connection (SPC) is a combination of a permanent connection at the source user-to-network side, a permanent connection at the destination user-to-network side, and a switched connection within the network. An Element Management System (EMS) or a Network Management System (NMS) typically initiates the establishment of the switched connection by communicating with the node that initiates the switched connection (also known as the ingress node). The latter then sets the connection using the distributed GMPLS signaling protocol. For the SPC, the communication method between the EMS/NMS and the ingress node is beyond the scope of this document (as it is for any other function described in this document).
软永久连接（SPC）是源用户到网络侧的永久连接、目标用户到网络侧的永久连接以及网络内的交换连接的组合。元件管理系统（EMS）或网络管理系统（NMS）通常通过与发起交换连接的节点（也称为入口节点）通信来发起交换连接的建立。后者然后使用分布式GMPLS信令协议设置连接。对于SPC，EMS/NMS和入口节点之间的通信方法超出了本文件的范围（与本文件中描述的任何其他功能一样）。
The end-to-end connection is thus created by associating the incoming interface of the ingress node with the switched connection within the network, along with the outgoing interface of the switched connection terminating network node (also referred to as egress node). An SPC connection is illustrated in the following figure. This shows the user's node A connected to a provider's node B via link #1, the user's node Z connected to a provider's node Y via link #3, and an abstract link #2 connecting the provider's node B and node Y. Nodes B and Y are referred to as the ingress and egress (respectively) of the network switched connection.
因此，通过将入口节点的输入接口与网络内的交换连接以及交换连接终止网络节点（也称为出口节点）的输出接口相关联来创建端到端连接。SPC连接如下图所示。这显示了用户节点A通过链路1连接到提供商节点B，用户节点Z通过链路3连接到提供商节点Y，以及连接提供商节点B和节点Y的抽象链路2。节点B和Y分别称为入口和出口网络交换连接的安全性。
--- --- --- ---
| A |--1--| B |-----2-//------| Y |--3--| Z |
--- --- --- ---
--- --- --- ---
| A |--1--| B |-----2-//------| Y |--3--| Z |
--- --- --- ---
In this instance, the connection on link #1 and link #3 are both provisioned (permanent connections that may be simple links). In contrast, the connection over link #2 is set up using the distributed control plane. Thus, the SPC is composed of the stitching of link #1, #2, and #3.
在本例中，链路#1和链路#3上的连接都已设置（可能是简单链路的永久连接）。相反，链路#2上的连接是使用分布式控制平面建立的。因此，SPC由链接#1、#2和#3的缝合组成。
Thus, to support the capability of requesting an SPC connection:
因此，为了支持请求SPC连接的能力：
- The GMPLS signaling protocol MUST be capable of supporting the ability to indicate the outgoing link and label information used when setting up the destination provisioned connection.
- GMPLS信令协议必须能够支持在设置目的地供应连接时指示使用的传出链路和标签信息的能力。
- In addition, due to the inter-domain applicability of ASON networks, the GMPLS signaling protocol SHOULD also support indication of the service level requested for the SPC. In cases where an SPC spans multiple domains, indication of both source and destination endpoints controlling the SPC request MAY be needed. These MAY be done via the source and destination signaling controller addresses.
- 此外，由于ASON网络的域间适用性，GMPLS信令协议还应支持指示SPC请求的服务级别。如果SPC跨越多个域，则可能需要指示控制SPC请求的源和目标端点。这些可以通过源和目标信令控制器地址来完成。
Note that the association at the ingress node, between the permanent connection and the switched connection, is an implementation matter that may be under the control of the EMS/NMS and is not within the scope of the signaling protocol. Therefore, it is outside the scope of this document.
注意，入口节点处的永久连接和交换连接之间的关联是可能在EMS/NMS的控制下并且不在信令协议的范围内的实现事项。因此，它不在本文件的范围内。
A call may be simply described as "An association between endpoints that supports an instance of a service" [ITU-T-G.8080]. Thus, it can be considered a service provided between two end-points, wherein several calls may exist between them. Multiple connections may be associated with each call. The call concept provides an abstract relationship between two users. This relationship describes (or verifies) the extent to which users are willing to offer (or accept) service to/from each other. Therefore, a call does not provide the actual connectivity for transmitting user traffic; it only builds a relationship by which subsequent connections may be made.
调用可以简单地描述为“支持服务实例的端点之间的关联”[ITU-T-G.8080]。因此，可以将其视为在两个端点之间提供的服务，其中它们之间可能存在多个调用。多个连接可能与每个呼叫相关联。调用概念提供了两个用户之间的抽象关系。这种关系描述（或验证）用户愿意向彼此提供（或接受）服务的程度。因此，呼叫不提供用于传输用户业务的实际连接；它只建立一种关系，通过这种关系可以建立后续连接。
A call MAY be associated with zero, one, or multiple connections. For the same call, connections MAY be of different types and each connection MAY exist independently of other connections (i.e., each connection is setup and released with separate signaling messages).
呼叫可能与零、一或多个连接相关联。对于同一呼叫，连接可以是不同类型的，并且每个连接可以独立于其他连接而存在（即，每个连接是通过单独的信令消息建立和释放的）。
The concept of the call allows for a better flexibility in how end-points set up connections and how networks offer services to users. For example, a call allows:
呼叫的概念允许在端点如何建立连接以及网络如何向用户提供服务方面具有更好的灵活性。例如，呼叫允许：
- An upgrade strategy for control plane operations, where a call control component (service provisioning) may be separate from the actual nodes hosting the connections (where the connection control component may reside).
- 一种用于控制平面操作的升级策略，其中呼叫控制组件（服务供应）可能与承载连接的实际节点（连接控制组件可能驻留的位置）分离。
- Identification of the call initiator (with both network call controller, as well as destination user) prior to connection, which may result in decreasing contention during resource reservation.
- 连接前识别呼叫发起方（包括网络呼叫控制器和目标用户），这可能会减少资源预留期间的争用。
- General treatment of multiple connections, which may be associated for several purposes; for example, a pair of working and recovery connections may belong to the same call.
- 多个连接的一般处理，这些连接可能有多种用途；例如，一对工作连接和恢复连接可能属于同一个呼叫。
To support the introduction of the call concept, GMPLS signaling SHOULD include a call identification mechanism and SHOULD allow for end-to-end call capability exchange.
为了支持呼叫概念的引入，GMPLS信令应包括呼叫识别机制，并应允许端到端呼叫能力交换。
For instance, a feasible structure for the call identifier (to guarantee global uniqueness) MAY concatenate a globally unique fixed ID (e.g., may be composed of country code or carrier code) with an operator specific ID (where the operator specific ID may be composed of a unique access point code - such as source node address - and a local identifier). Other formats SHALL also be possible, depending on the call identification conventions between the parties involved in the call setup process.
例如，呼叫标识符的可行结构（以保证全局唯一性）可以将全局唯一的固定ID（例如，可以由国家代码或载波代码组成）与特定于运营商的ID连接起来（其中，特定于运营商的ID可能由唯一的接入点代码（如源节点地址）和本地标识符组成）。也可以使用其他格式，具体取决于参与呼叫设置过程的各方之间的呼叫识别约定。
As described in [ITU-T-G.8080], call segmentation MAY be applied when a call crosses several control domains. As such, when the call traverses multiple control domains, an end-to-end call MAY consist of multiple call segments. For a given end-to-end call, each call segment MAY have one or more associated connections, and the number of connections associated with each call segment MAY be different.
如[ITU-T-G.8080]所述，当呼叫跨越多个控制域时，可以应用呼叫分段。因此，当呼叫穿越多个控制域时，端到端呼叫可能由多个呼叫段组成。对于给定的端到端呼叫，每个呼叫段可能有一个或多个关联连接，并且与每个呼叫段关联的连接数可能不同。
The initiating caller interacts with the called party by means of one or more intermediate network call controllers, located at control domain boundaries (i.e., at inter-domain reference points, UNI or E-NNI). Call segment capabilities are defined by the policies associated at these reference points.
发起呼叫方通过位于控制域边界（即域间参考点UNI或e-NNI）的一个或多个中间网络呼叫控制器与被叫方交互。呼叫段功能由在这些参考点关联的策略定义。
This capability allows for independent (policy based) choices of signaling, concatenation, data plane protection, and control plane driven recovery paradigms in different control domains.
此功能允许在不同控制域中独立（基于策略）选择信令、连接、数据平面保护和控制平面驱动的恢复模式。
Various types of failures may occur, affecting the ASON control plane. Requirements placed on control plane failure recovery by [ITU-T-G.8080] include:
可能会发生各种类型的故障，影响ASON控制平面。[ITU-T-G.8080]对控制平面故障恢复的要求包括：
- Any control plane failure (i.e., single or multiple control channel and/or controller failure and any combination thereof) MUST NOT result in releasing established calls and connections (including the corresponding transport plane connections).
- 任何控制平面故障（即，单个或多个控制通道和/或控制器故障及其任何组合）不得导致释放已建立的呼叫和连接（包括相应的传输平面连接）。
- Upon recovery from a control plane failure, the recovered control entity MUST have the ability to recover the status of the calls and the connections established before failure occurrence.
- 从控制平面故障恢复后，恢复的控制实体必须能够恢复故障发生前建立的呼叫和连接的状态。
- Upon recovery from a control plane failure, the recovered control entity MUST have the ability to recover the connectivity information of its neighbors.
- 从控制平面故障恢复后，恢复的控制实体必须能够恢复其邻居的连接信息。
- Upon recovery from a control plane failure, the recovered control entity MUST have the ability to recover the association between the call and its associated connections.
- 从控制平面故障恢复后，恢复的控制实体必须能够恢复调用与其关联连接之间的关联。
- Upon recovery from a control plane failure, calls and connections in the process of being established (i.e., pending call/connection setup requests) SHOULD be released or continued (with setup).
- 从控制平面故障恢复后，应释放或继续建立过程中的呼叫和连接（即挂起的呼叫/连接设置请求）（使用设置）。
- Upon recovery from a control plane failure, calls and connections in the process of being released MUST be released.
- 从控制平面故障中恢复后，必须释放释放过程中的调用和连接。
It is an ASON requirement to enable support for G.805 [ITU-T-G.805] serial compound links. The text below provides an illustrative example of such a scenario, and the associated requirements.
ASON要求支持G.805[ITU-T-G.805]串行复合链路。下文提供了此类场景的示例以及相关需求。
Labels are defined in GMPLS (see [RFC3471]) to provide information on the resources used on a link local basis for a particular connection. The labels may range from specifying a particular timeslot, indicating a particular wavelength, or to identifying a particular port/fiber. In the ASON context, the value of a label may not be consistent across a link. For example, the figure below illustrates
GMPLS（参见[RFC3471]）中定义了标签，以提供特定连接在本地链路上使用的资源信息。标签的范围可以从指定特定时隙、指示特定波长到识别特定端口/光纤。在ASON上下文中，标签的值在整个链路中可能不一致。例如，下图说明了
the case where two GMPLS capable nodes (A and Z) are interconnected across two non-GMPLS capable nodes (B and C), where all of these nodes are SONET/SDH nodes, providing, for example, a VC-4 service.
两个支持GMPLS的节点（A和Z）跨两个不支持GMPLS的节点（B和C）互连的情况，其中所有这些节点都是SONET/SDH节点，提供例如VC-4服务。
----- -----
| | --- --- | |
| A |---| B |---| C |---| Z |
| | --- --- | |
----- -----
----- -----
| | --- --- | |
| A |---| B |---| C |---| Z |
| | --- --- | |
----- -----
Labels have an associated implicit imposed structure based on [GMPLS-SONET] and [GMPLS-OTN]. Thus, once the local label is exchanged with its neighboring control plane node, the structure of the local label may not be significant to the neighbor node, as the association between the local and the remote label may not necessarily be the same. This issue does not present a problem in simple point-to-point connections between two control plane-enabled nodes in which the timeslots are mapped 1:1 across the interface. However, if a non-GMPLS capable sub-network is introduced between these nodes (as in the above figure, where the sub-network provides re-arrangement capability for the timeslots), label scoping may become an issue.
标签具有基于[GMPLS-SONET]和[GMPLS-OTN]的相关隐式强制结构。因此，一旦本地标签与其相邻控制平面节点交换，本地标签的结构对于相邻节点可能不重要，因为本地标签和远程标签之间的关联不一定相同。在启用控制平面的两个节点之间的简单点对点连接中，此问题不会出现问题，在这两个节点中，时隙在接口上以1:1的比例映射。然而，如果在这些节点之间引入不支持GMPLS的子网（如上图所示，子网为时隙提供重新安排能力），则标签范围可能成为一个问题。
In this context, there is an implicit assumption that the data plane connections between the GMPLS capable edges already exist prior to any connection request. For instance, node A's outgoing VC-4's timeslot #1 (with SUKLM label=[1,0,0,0,0]), as defined in [GMPLS-SONET]), may be mapped onto node B's outgoing VC-4's timeslot #6 (label=[6,0,0,0,0]), or may be mapped onto node C's outgoing VC-4's timeslot #4 (label=[4,0,0,0,0]). Thus, by the time node Z receives the request from node A with label=[1,0,0,0,0], node Z's local label and timeslot no longer correspond to the received label and timeslot information.
在这种情况下，有一个隐含的假设，即在任何连接请求之前，支持GMPLS的边缘之间的数据平面连接已经存在。例如，[GMPLS-SONET]中定义的节点A的传出VC-4的时隙#1（具有SUKLM标签=[1,0,0,0]），可以映射到节点B的传出VC-4的时隙#6（标签=[6,0,0,0,0]），或者可以映射到节点C的传出VC-4的时隙#4（标签=[4,0,0,0,0]）。因此，当节点Z从节点A接收到标签为[1,0,0,0,0]的请求时，节点Z的本地标签和时隙不再对应于接收到的标签和时隙信息。
As such, to support this capability, a label association mechanism SHOULD be used by the control plane node to map the received (remote) label into a locally significant label. The information necessary to allow mapping from a received label value to a locally significant label value can be derived in several ways including:
因此，为了支持此功能，控制平面节点应使用标签关联机制将接收到的（远程）标签映射为本地有效标签。允许从接收到的标签值映射到本地有效标签值所需的信息可以通过以下几种方式导出：
- Manual provisioning of the label association
- 手动设置标签关联
- Discovery of the label association
- 标签关联的发现
Either method MAY be used. In case of dynamic association, the discovery mechanism operates at the timeslot/label level before the connection request is processed at the ingress node. Note that in the case where two nodes are directly connected, no association is
两种方法均可使用。在动态关联的情况下，发现机制在入口节点处理连接请求之前在时隙/标签级别运行。注意，在两个节点直接连接的情况下，没有关联
required. In particular, for directly connected TDM interfaces, no mapping function (at all) is required due to the implicit label structure (see [GMPLS-SONET] and [GMPLS-OTN]). In these instances, the label association function provides a one-to-one mapping of the received to local label values.
必修的。特别是，对于直接连接的TDM接口，由于隐式标签结构（参见[GMPLS-SONET]和[GMPLS-OTN]），因此不需要任何映射功能。在这些情况下，标签关联函数提供接收到的标签值到本地标签值的一对一映射。
Crankback has been identified as an important requirement for ASON networks. Upon a setup failure, it allows a connection setup request to be retried on an alternate path that detours around a blocked link or node (e.g., because a link or a node along the selected path has insufficient resources).
回退已被确定为ASON网络的一项重要要求。设置失败时，它允许在绕过阻塞链路或节点的备用路径上重试连接设置请求（例如，因为沿所选路径的链路或节点资源不足）。
Crankback mechanisms MAY also be applied during connection recovery by indicating the location of the failed link or node. This would significantly improve the successful recovery ratio for failed connections, especially in situations where a large number of setup requests are simultaneously triggered.
通过指示故障链路或节点的位置，也可以在连接恢复期间应用回退机制。这将显著提高失败连接的成功恢复率，特别是在同时触发大量安装请求的情况下。
The following mechanisms are assumed during crankback signaling:
在拖转启动信号期间，假设以下机制：
- The blocking resource (link or node) MUST be identified and returned in the error response message to the repair node (that may or may not be the ingress node); it is also assumed that this process will occur within a limited period of time.
- 必须识别阻塞资源（链路或节点），并在错误响应消息中返回给修复节点（可能是入口节点，也可能不是入口节点）；还假设该过程将在有限的时间内发生。
- The computation (from the repair node) of an alternate path around the blocking link or node that satisfies the initial connection constraints.
- （从修复节点）计算满足初始连接约束的阻塞链路或节点周围的备用路径。
- The re-initiation of the connection setup request from the repair node (i.e., the node that has intercepted and processed the error response message).
- 从修复节点（即已截获并处理错误响应消息的节点）重新启动连接设置请求。
The following properties are expected for crankback signaling:
回退信号应具有以下特性：
- Error information persistence: the entity that computes the alternate (re-routing) path SHOULD store the identifiers of the blocking resources, as indicated in the error message, until the connection is successfully established or until the node abandons rerouting attempts. Since crankback may happen more than once while establishing a specific connection, the history of all experienced blockages for this connection SHOULD be maintained (at least until the routing protocol updates the state of this information) to perform an accurate path computation that will avoid all blockages.
- 错误信息持久性：计算备用（重路由）路径的实体应存储阻塞资源的标识符，如错误消息中所示，直到成功建立连接或节点放弃重路由尝试。由于在建立特定连接时可能会发生多次回退，因此应保持此连接所有经历过的阻塞的历史记录（至少在路由协议更新此信息的状态之前），以执行将避免所有阻塞的准确路径计算。
- Rerouting attempts limitation: to prevent an endless repetition of connection setup attempts (using crankback information), the number of retries SHOULD be strictly limited. The maximum number of crankback rerouting attempts allowed MAY be limited per connection or per node:
- 重新路由尝试限制：为了防止连接设置尝试的无休止重复（使用回退信息），应严格限制重试次数。每个连接或每个节点允许的最大回退重新路由尝试次数可能会受到限制：
- When the number of retries at a particular node is exceeded, the node that is currently handling the failure reports the error message upstream to the next repair node, where further rerouting attempts MAY be performed. It is important that the crankback information provided indicate that re-routing through this node will not succeed.
- 当超过特定节点的重试次数时，当前正在处理故障的节点将向上游的下一个修复节点报告错误消息，在那里可能会执行进一步的重新路由尝试。重要的是，提供的回退信息表明通过此节点的重新路由将不会成功。
- When the maximum number of retries for a specific connection has been exceeded, the repair node that is handling the current failure SHOULD send an error message upstream to indicate the "Maximum number of re-routings exceeded". This error message will be sent back to the ingress node with no further rerouting attempts. Then, the ingress node MAY choose to retry the connection setup according to local policy, using its original path, or computing a path that avoids the blocking resources.
- 当超过特定连接的最大重试次数时，处理当前故障的修复节点应向上游发送错误消息，以指示“超出的最大重新路由次数”。此错误消息将发送回入口节点，无需进一步重新路由尝试。然后，入口节点可以选择根据本地策略、使用其原始路径或计算避免阻塞资源的路径来重试连接设置。
Note: After several retries, a given repair point MAY be unable to compute a path to the destination node that avoids all of the blockages. In this case, it MUST pass the error message upstream to the next repair point.
注意：在多次重试后，给定的修复点可能无法计算到目标节点的路径，从而避免所有阻塞。在这种情况下，它必须将错误消息向上游传递到下一个修复点。
To support the ASON network, the following additional category of error cases are defined:
为支持ASON网络，定义了以下额外类别的错误情况：
- Errors associated with basic call and soft permanent connection support. For example, these MAY include incorrect assignment of IDs for the Call or an invalid interface ID for the soft permanent connection.
- 与基本呼叫和软永久连接支持相关的错误。例如，这些可能包括调用的ID分配不正确，或软永久连接的接口ID无效。
- Errors associated with policy failure during processing of the new call and soft permanent connection capabilities. These MAY include unauthorized requests for the particular capability.
- 处理新呼叫和软永久连接功能期间与策略失败相关的错误。这些可能包括对特定功能的未经授权的请求。
- Errors associated with incorrect specification of the service level.
- 与不正确的服务级别规范相关的错误。
As noted above, in support of GMPLS protocol requirements, any extensions to the GMPLS signaling protocol, in support of the requirements described in this document, MUST be backward compatible.
如上所述，为支持GMPLS协议要求，为支持本文件所述要求而对GMPLS信令协议进行的任何扩展必须向后兼容。
Backward compatibility means that in a network of nodes, where some support GMPLS signaling extensions to facilitate the functions described in this document, and some do not, it MUST be possible to set up conventional connections (as described by [RFC3473]) between any arbitrary pair of nodes and to traverse any arbitrary set of nodes. Further, the use of any GMPLS signaling extensions to set up calls or connections that support the functions described in this document MUST not perturb existing conventional connections.
向后兼容性意味着，在节点网络中，有些支持GMPLS信令扩展以促进本文档中描述的功能，有些不支持，必须能够在任意一对节点之间建立常规连接（如[RFC3473]所述），并遍历任意一组节点。此外，使用任何GMPLS信令扩展建立支持本文件所述功能的呼叫或连接不得干扰现有的常规连接。
Additionally, when transit nodes that do not need to participate in the new functions described in this document lie on the path of a call or connection, the GMPLS signaling extensions MUST be such that those transit nodes are able to participate in the establishment of a call or connection by passing the setup information onwards, unmodified.
此外，当不需要参与本文档中描述的新功能的中转节点位于呼叫或连接的路径上时，GMPLS信令扩展必须使得这些中转节点能够通过向前传递设置信息（未经修改）来参与呼叫或连接的建立。
Lastly, when a transit or egress node is called upon to support a function described in this document, but does not support the function, the GMPLS signaling extensions MUST be such that they can be rejected by pre-existing GMPLS signaling mechanisms in a way that is not detrimental to the network as a whole.
最后，当中转或出口节点被调用以支持本文档中描述的功能，但不支持该功能时，GMPLS信令扩展必须能够被预先存在的GMPLS信令机制以不损害整个网络的方式拒绝。
Per [ITU-T-G.8080], it is not possible to establish a connection in advance of call setup completion. Also, policy and authentication procedures are applied prior to the establishment of the call (and can then also be restricted to connection establishment in the context of this call).
根据[ITU-T-G.8080]，不可能在呼叫设置完成之前建立连接。此外，在建立呼叫之前应用策略和身份验证过程（然后也可以限制在此呼叫上下文中建立连接）。
This document introduces no new security requirements to GMPLS signaling (see [RFC3471]).
本文件未对GMPLS信令提出新的安全要求（见[RFC3471]）。
The authors would like to thank Nic Larkin, Osama Aboul-Magd, and Dimitrios Pendarakis for their contribution to the previous version of this document, Zhi-Wei Lin for his contribution to this document, Deborah Brungard for her input and guidance in our understanding of the ASON model, and Gert Grammel for his decryption effort during the reduction of some parts of this document.
作者感谢Nic Larkin、Osama Aboul Magd和Dimitrios Pendarakis对本文件前一版本的贡献，感谢林志伟对本文件的贡献，感谢Deborah Brungard对我们理解ASON模型的投入和指导，和Gert Grammel，感谢他在减少文档某些部分的过程中所做的解密工作。
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2119]Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，1997年3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。
[RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC 3473, January 2003.
[RFC3473]Berger，L.“通用多协议标签交换（GMPLS）信令资源预留协议流量工程（RSVP-TE）扩展”，RFC 3473，2003年1月。
[ANSI-T1.105] ANSI, "Synchronous Optical Network (SONET): Basic Description Including Multiplex Structure, Rates, and Formats", T1.105, October 2000.
[ANSI-T1.105]ANSI，“同步光网络（SONET）：基本描述，包括多路复用结构、速率和格式”，T1.105，2000年10月。
[GMPLS-OTN] Papadimitriou, D., Ed., "Generalized MPLS (GMPLS) Signaling Extensions for G.709 Optical Transport Networks Control", Work in Progress, January 2005.
[GMPLS-OTN]Papadimitriou，D.，编辑，“G.709光传输网络控制的通用MPLS（GMPLS）信令扩展”，正在进行的工作，2005年1月。
[GMPLS-OVERLAY] Swallow, G., Drake, J., Ishimatsu, H., and Y. Rekhter, "Generalize Multiprotocol Label Switching (GMPLS) User-Network Interface (UNI): Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Support for the Overlay Model", Work in Progress, October 2004.
[GMPLS-OVERLAY]Swallow，G.，Drake，J.，Ishimatsu，H.，和Y.Rekhter，“通用化多协议标签交换（GMPLS）用户网络接口（UNI）：覆盖模型的资源预留协议流量工程（RSVP-TE）支持”，正在进行的工作，2004年10月。
[GMPLS-SONET] Mannie, E. and D. Papadimitriou, "Generalized Multi-Protocol Label Switching (GMPLS) Extensions for Synchronous Optical Network (SONET) and Synchronous Digital Hierarchy (SDH) Control", RFC 3946, October 2004.
[GMPLS-SONET]Mannie，E.和D.Papadimitriou，“同步光网络（SONET）和同步数字体系（SDH）控制的通用多协议标签交换（GMPLS）扩展”，RFC 3946，2004年10月。
[GMPLS-VPN] Ould-Brahim, H. and Y. Rekhter, Eds., "GVPN Services: Generalized VPN Services using BGP and GMPLS Toolkit", Work in Progress, May 2004.
[GMPLS-VPN]Ould Brahim，H.和Y.Rekhter编辑，“GVPN服务：使用BGP和GMPLS工具包的通用VPN服务”，正在进行的工作，2004年5月。
[ITU-T-G.707] ITU-T, "Network Node Interface for the Synchronous Digital Hierarchy (SDH)", Recommendation G.707, October 2000.
[ITU-T-G.707]ITU-T，“同步数字体系（SDH）的网络节点接口”，建议G.707，2000年10月。
[ITU-T-G.709] ITU-T, "Interface for the Optical Transport Network (OTN)", Recommendation G.709 (and Amendment 1), February 2001 (October 2001). http://www.itu.int
[ITU-T-G.709]ITU-T，“光传输网络（OTN）接口”，建议G.709（和修正案1），2001年2月（2001年10月）。http://www.itu.int
[ITU-T-G.7713] ITU-T "Distributed Call and Connection Management", Recommendation G.7713/Y.1304, November 2001. http://www.itu.int
[ITU-T-G.7713]ITU-T“分布式呼叫和连接管理”，建议G.7713/Y.13042001年11月。http://www.itu.int
[ITU-T-G.805] ITU-T, "Generic functional architecture of transport networks)", Recommendation G.805, March 2000. http://www.itu.int
[ITU-T-G.805]ITU-T，“传输网络的通用功能架构”，建议G.805，2000年3月。http://www.itu.int
[ITU-T-G.8080] ITU-T "Architecture for the Automatically Switched Optical Network (ASON)", Recommendation G.8080/Y.1304, November 2001 (and Revision, January 2003). http://www.itu.int
[ITU-T-G.8080]ITU-T“自动交换光网络（ASON）的体系结构”，建议G.8080/Y.13042001年11月（修订版，2003年1月）。http://www.itu.int
Appendix - Terminology
附录-术语
This document makes use of the following terms:
本文件使用了以下术语：
Administrative domain: See Recommendation G.805 [ITU-T-G.805].
行政领域：见建议G.805[ITU-T-G.805]。
Call: Association between endpoints that supports an instance of a service.
调用：支持服务实例的端点之间的关联。
Connection: Concatenation of link connections and sub-network connections that allows the transport of user information between the ingress and egress points of a sub-network.
连接：链路连接和子网连接的连接，允许在子网的入口和出口点之间传输用户信息。
Control Plane: Performs the call control and connection control functions. The control plane sets up and releases connections through signaling, and may restore a connection in case of a failure.
控制平面：执行呼叫控制和连接控制功能。控制平面通过信令建立和释放连接，并可在发生故障时恢复连接。
(Control) Domain: Represents a collection of entities that are grouped for a particular purpose. G.8080 applies this G.805 recommendation concept (that defines two particular forms: the administrative domain and the management domain) to the control plane in the form of a control domain. Entities grouped in a control domain are components of the control plane.
（控制）域：表示为特定目的分组的实体集合。G.8080以控制域的形式将G.805建议概念（定义了两种特定形式：管理域和管理域）应用于控制平面。在控制域中分组的实体是控制平面的组件。
External NNI (E-NNI): Interfaces are located between protocol controllers that are situated between control domains.
外部NNI（E-NNI）：接口位于控制域之间的协议控制器之间。
Internal NNI (I-NNI): Interfaces are located between protocol controllers within control domains.
内部NNI（I-NNI）：接口位于控制域内的协议控制器之间。
Link: See Recommendation G.805 [ITU-T-G.805].
链接：见建议G.805[ITU-T-G.805]。
Management Plane: Performs management functions for the Transport Plane, the control plane, and the system as a whole. It also provides coordination between all the planes. The following management functional areas are performed in the management plane: performance, fault, configuration, accounting, and security management.
管理平面：对运输平面、控制平面和整个系统执行管理功能。它还提供所有平面之间的协调。在管理平面中执行以下管理功能区域：性能、故障、配置、记帐和安全管理。
Management Domain: See Recommendation G.805 [ITU-T-G.805].
管理领域：见建议G.805[ITU-T-G.805]。
Transport Plane: Provides bi-directional or unidirectional transfer of user information, from one location to another. It can also provide transfer of some control and network management information. The Transport Plane is layered and is equivalent to the Transport Network defined in G.805 [ITU-T-G.805].
传输平面：提供用户信息从一个位置到另一个位置的双向或单向传输。它还可以提供一些控制和网络管理信息的传输。传输平面是分层的，相当于G.805[ITU-T-G.805]中定义的传输网络。
User Network Interface (UNI): Interfaces are located between protocol controllers, between a user and a control domain.
用户网络接口（UNI）：接口位于协议控制器之间、用户和控制域之间。
Authors' Addresses
作者地址
Dimitri Papadimitriou Alcatel Francis Wellesplein 1, B-2018 Antwerpen, Belgium
迪米特里·帕帕迪米特里奥·阿尔卡特弗朗西斯·韦勒斯普林1号，B-2018比利时安特卫普
Phone: +32 3 2408491
EMail: dimitri.papadimitriou@alcatel.be
Phone: +32 3 2408491
EMail: dimitri.papadimitriou@alcatel.be
John Drake Boeing Satellite Systems 2300 East Imperial Highway El Segundo, CA 90245
约翰德雷克波音卫星系统2300东帝国公路埃尔塞贡多，加利福尼亚州90245
EMail: John.E.Drake2@boeing.com
EMail: John.E.Drake2@boeing.com
Adrian Farrel Old Dog Consulting
阿德里安·法雷尔老狗咨询公司
Phone: +44 (0) 1978 860944
EMail: adrian@olddog.co.uk
Phone: +44 (0) 1978 860944
EMail: adrian@olddog.co.uk
Gerald R. Ash ATT AT&T Labs, Room MT D5-2A01 200 Laurel Avenue Middletown, NJ 07748, USA
美国新泽西州劳雷尔大道米德尔顿200号MT D5-2A01室美国电话电报公司实验室杰拉尔德R.阿什07748
EMail: gash@att.com
EMail: gash@att.com
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Lyndon Ong Ciena邮政信箱308号，加利福尼亚州库比蒂诺，邮编95015，美国
EMail: lyong@ciena.com
EMail: lyong@ciena.com
Full Copyright Statement
完整版权声明
Copyright (C) The Internet Society (2005).
版权所有（C）互联网协会（2005年）。
This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights.
本文件受BCP 78中包含的权利、许可和限制的约束，除其中规定外，作者保留其所有权利。
This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
本文件及其包含的信息是按“原样”提供的，贡献者、他/她所代表或赞助的组织（如有）、互联网协会和互联网工程任务组不承担任何明示或暗示的担保，包括但不限于任何保证，即使用本文中的信息不会侵犯任何权利，或对适销性或特定用途适用性的任何默示保证。
Intellectual Property
知识产权
The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79.
IETF对可能声称与本文件所述技术的实施或使用有关的任何知识产权或其他权利的有效性或范围，或此类权利下的任何许可可能或可能不可用的程度，不采取任何立场；它也不表示它已作出任何独立努力来确定任何此类权利。有关RFC文件中权利的程序信息，请参见BCP 78和BCP 79。
Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr.
向IETF秘书处披露的知识产权副本和任何许可证保证，或本规范实施者或用户试图获得使用此类专有权利的一般许可证或许可的结果，可从IETF在线知识产权存储库获取，网址为http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org.
IETF邀请任何相关方提请其注意任何版权、专利或专利申请，或其他可能涵盖实施本标准所需技术的专有权利。请将信息发送至IETF的IETF-ipr@ietf.org.
Acknowledgement
确认
Funding for the RFC Editor function is currently provided by the Internet Society.
RFC编辑功能的资金目前由互联网协会提供。