Internet Engineering Task Force (IETF) Y. Lee, Ed.
Request for Comments: 6566 Huawei
Category: Informational G. Bernstein, Ed.
ISSN: 2070-1721 Grotto Networking
D. Li
Huawei
G. Martinelli
Cisco
March 2012
Internet Engineering Task Force (IETF) Y. Lee, Ed.
Request for Comments: 6566 Huawei
Category: Informational G. Bernstein, Ed.
ISSN: 2070-1721 Grotto Networking
D. Li
Huawei
G. Martinelli
Cisco
March 2012
A Framework for the Control of Wavelength Switched Optical Networks (WSONs) with Impairments
一种有损伤的波长交换光网络控制框架
Abstract
摘要
As an optical signal progresses along its path, it may be altered by the various physical processes in the optical fibers and devices it encounters. When such alterations result in signal degradation, these processes are usually referred to as "impairments". These physical characteristics may be important constraints to consider when using a GMPLS control plane to support path setup and maintenance in wavelength switched optical networks.
当光信号沿着其路径前进时，它可能会被它遇到的光纤和设备中的各种物理过程所改变。当这种改变导致信号退化时，这些过程通常被称为“损伤”。当使用GMPLS控制平面来支持波长交换光网络中的路径设置和维护时，这些物理特性可能是重要的约束条件。
This document provides a framework for applying GMPLS protocols and the Path Computation Element (PCE) architecture to support Impairment-Aware Routing and Wavelength Assignment (IA-RWA) in wavelength switched optical networks. Specifically, this document discusses key computing constraints, scenarios, and architectural processes: routing, wavelength assignment, and impairment validation. This document does not define optical data plane aspects; impairment parameters; or measurement of, or assessment and qualification of, a route; rather, it describes the architectural and information components for protocol solutions.
本文档提供了一个应用GMPLS协议和路径计算元素（PCE）体系结构的框架，以支持波长交换光网络中的损伤感知路由和波长分配（IA-RWA）。具体而言，本文档讨论了关键的计算约束、场景和体系结构过程：路由、波长分配和损伤验证。本文件未定义光学数据平面方面；减值参数；路线的测量、评估和鉴定；相反，它描述了协议解决方案的体系结构和信息组件。
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/rfc6566.
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/rfc6566.
Copyright Notice
版权公告
Copyright (c) 2012 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2012 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
2. Terminology .....................................................4
3. Applicability ...................................................6
4. Impairment-Aware Optical Path Computation .......................7
4.1. Optical Network Requirements and Constraints ...............8
4.1.1. Impairment-Aware Computation Scenarios ..............9
4.1.2. Impairment Computation and
Information-Sharing Constraints ....................10
4.1.3. Impairment Estimation Process ......................11
4.2. IA-RWA Computation and Control Plane Architectures ........13
4.2.1. Combined Routing, WA, and IV .......................15
4.2.2. Separate Routing, WA, or IV ........................15
4.2.3. Distributed WA and/or IV ...........................16
4.3. Mapping Network Requirements to Architectures .............16
5. Protocol Implications ..........................................19
5.1. Information Model for Impairments .........................19
5.2. Routing ...................................................20
5.3. Signaling .................................................21
5.4. PCE .......................................................21
5.4.1. Combined IV & RWA ..................................21
5.4.2. IV-Candidates + RWA ................................22
5.4.3. Approximate IA-RWA + Separate Detailed-IV ..........24
6. Manageability and Operations ...................................25
7. Security Considerations ........................................26
8. References .....................................................27
8.1. Normative References ......................................27
8.2. Informative References ....................................27
9. Contributors ...................................................29
1. Introduction ....................................................3
2. Terminology .....................................................4
3. Applicability ...................................................6
4. Impairment-Aware Optical Path Computation .......................7
4.1. Optical Network Requirements and Constraints ...............8
4.1.1. Impairment-Aware Computation Scenarios ..............9
4.1.2. Impairment Computation and
Information-Sharing Constraints ....................10
4.1.3. Impairment Estimation Process ......................11
4.2. IA-RWA Computation and Control Plane Architectures ........13
4.2.1. Combined Routing, WA, and IV .......................15
4.2.2. Separate Routing, WA, or IV ........................15
4.2.3. Distributed WA and/or IV ...........................16
4.3. Mapping Network Requirements to Architectures .............16
5. Protocol Implications ..........................................19
5.1. Information Model for Impairments .........................19
5.2. Routing ...................................................20
5.3. Signaling .................................................21
5.4. PCE .......................................................21
5.4.1. Combined IV & RWA ..................................21
5.4.2. IV-Candidates + RWA ................................22
5.4.3. Approximate IA-RWA + Separate Detailed-IV ..........24
6. Manageability and Operations ...................................25
7. Security Considerations ........................................26
8. References .....................................................27
8.1. Normative References ......................................27
8.2. Informative References ....................................27
9. Contributors ...................................................29
Wavelength Switched Optical Networks (WSONs) are constructed from subsystems that may include wavelength division multiplexed links, tunable transmitters and receivers, Reconfigurable Optical Add/Drop Multiplexers (ROADMs), wavelength converters, and electro-optical network elements. A WSON is a Wavelength Division Multiplexing (WDM)-based optical network in which switching is performed selectively based on the center wavelength of an optical signal.
波长交换光网络（WSON）由子系统构成，子系统可包括波分复用链路、可调谐发射机和接收机、可重构光分插复用器（ROADM）、波长转换器和电光网络元件。WSON是基于波分复用（WDM）的光网络，其中根据光信号的中心波长选择性地执行切换。
As an optical signal progresses along its path, it may be altered by the various physical processes in the optical fibers and devices it encounters. When such alterations result in signal degradation, these processes are usually referred to as "impairments". Optical impairments accumulate along the path (without 3R regeneration [G.680]) traversed by the signal. They are influenced by the type of fiber used, the types and placement of various optical devices, and
当光信号沿着其路径前进时，它可能会被它遇到的光纤和设备中的各种物理过程所改变。当这种改变导致信号退化时，这些过程通常被称为“损伤”。光损伤沿着信号穿过的路径累积（无3R再生[G.680]）。它们受所用光纤类型、各种光学设备的类型和位置以及
the presence of other optical signals that may share a fiber segment along the signal's path. The degradation of the optical signals due to impairments can result in unacceptable bit error rates or even a complete failure to demodulate and/or detect the received signal.
可能沿信号路径共享光纤段的其他光信号的存在。由于损伤导致的光信号的劣化可导致不可接受的误码率，甚至导致解调和/或检测接收信号的完全失败。
In order to provision an optical connection (an optical path) through a WSON, a combination of path continuity, resource availability, and impairment constraints must be met to determine viable and optimal paths through the network. The determination of appropriate paths is known as Impairment-Aware Routing and Wavelength Assignment (IA-RWA).
为了通过WSON提供光连接（光路径），必须满足路径连续性、资源可用性和损伤约束的组合，以确定通过网络的可行和最佳路径。确定适当的路径称为损伤感知路由和波长分配（IA-RWA）。
Generalized Multi-Protocol Label Switching (GMPLS) [RFC3945] provides a set of control plane protocols that can be used to operate networks ranging from packet switch capable networks to those networks that use time division multiplexing and WDM. The Path Computation Element (PCE) architecture [RFC4655] defines functional computation components that can be used in cooperation with the GMPLS control plane to compute and suggest appropriate paths. [RFC4054] provides an overview of optical impairments and their routing (path selection) implications for GMPLS. This document uses [G.680] and other ITU-T Recommendations as references for the optical data plane aspects.
通用多协议标签交换（GMPLS）[RFC3945]提供了一组控制平面协议，可用于操作网络，从支持分组交换的网络到使用时分复用和WDM的网络。路径计算元素（PCE）体系结构[RFC4655]定义了可与GMPLS控制平面配合使用的功能计算组件，以计算和建议适当的路径。[RFC4054]概述了光学损伤及其对GMPLS的路由（路径选择）影响。本文件使用[G.680]和其他ITU-T建议作为光学数据平面方面的参考。
This document provides a framework for applying GMPLS protocols and the PCE architecture to the control and operation of IA-RWA for WSONs. To aid in this evaluation, this document provides an overview of the subsystems and processes that comprise WSONs and describes IA-RWA models based on the corresponding ITU-T Recommendations, so that the information requirements for use by GMPLS and PCE systems can be identified. This work will facilitate the development of protocol extensions in support of IA-RWA within the GMPLS and PCE protocol families.
本文件提供了一个框架，用于将GMPLS协议和PCE体系结构应用于无线传感器网络IA-RWA的控制和操作。为了帮助进行评估，本文件概述了组成WSON的子系统和过程，并根据相应的ITU-T建议描述了IA-RWA模型，以便确定GMPLS和PCE系统使用的信息要求。这项工作将促进协议扩展的开发，以支持GMPLS和PCE协议系列内的IA-RWA。
ADM: Add/Drop Multiplexer. An optical device used in WDM networks and composed of one or more line side ports and, typically, many tributary ports.
ADM：添加/删除多路复用器。一种用于波分复用（WDM）网络的光学设备，由一个或多个线路侧端口和多个支路端口组成。
Black Links: Black links refer to tributary interfaces where only link characteristics are defined. This approach enables transverse compatibility at the single-channel point using a direct wavelength-multiplexing configuration.
黑色链路：黑色链路指仅定义链路特性的支路接口。该方法使用直接波长复用配置在单信道点实现横向兼容性。
CWDM: Coarse Wavelength Division Multiplexing
粗波分复用
DGD: Differential Group Delay
差分群时延
DWDM: Dense Wavelength Division Multiplexing
密集波分复用
FOADM: Fixed Optical Add/Drop Multiplexer
FOADM：固定光分插复用器
GMPLS: Generalized Multi-Protocol Label Switching
广义多协议标签交换
IA-RWA: Impairment-Aware Routing and Wavelength Assignment
IA-RWA：损伤感知路由和波长分配
Line Side: In a WDM system, line side ports and links typically can carry the full multiplex of wavelength signals, as compared to tributary (add or drop ports), which typically carry a few (typically one) wavelength signals.
线路侧：在WDM系统中，线路侧端口和链路通常可以承载波长信号的完全多路复用，而支路（添加或删除端口）通常承载几个（通常是一个）波长信号。
NEs: Network Elements
网元：网元
OADMs: Optical Add/Drop Multiplexers
光分插复用器
OSNR: Optical Signal-to-Noise Ratio
OSNR：光信噪比
OXC: Optical Cross-Connect. An optical switching element in which a signal on any input port can reach any output port.
OXC：光交叉连接。一种光交换元件，其中任何输入端口上的信号都可以到达任何输出端口。
PCC: Path Computation Client. Any client application requesting that a path computation be performed by the Path Computation Element.
路径计算客户端。请求由路径计算元素执行路径计算的任何客户端应用程序。
PCE: Path Computation Element. An entity (component, application, or network node) that is capable of computing a network path or route based on a network graph and application of computational constraints.
PCE：路径计算元素。能够基于网络图和计算约束的应用计算网络路径或路由的实体（组件、应用程序或网络节点）。
PCEP: PCE Communication Protocol. The communication protocol between a Path Computation Client and Path Computation Element.
PCEP：PCE通信协议。路径计算客户端和路径计算元素之间的通信协议。
PXC: Photonic Cross-Connect
光子交叉连接
Q-Factor: The Q-factor provides a qualitative description of the receiver performance. It is a function of the optical signal-to-noise ratio. The Q-factor suggests the minimum SNR (Signal-to-Noise Ratio) required to obtain a specific bit error rate (BER) for a given signal.
Q因子：Q因子提供接收机性能的定性描述。它是光信噪比的函数。Q因子表示获得给定信号的特定误码率（BER）所需的最小SNR（信噪比）。
ROADM: Reconfigurable Optical Add/Drop Multiplexer. A wavelength-selective switching element featuring input and output line side ports as well as add/drop tributary ports.
ROADM：可重构光分插复用器。一种波长选择开关元件，具有输入和输出线路侧端口以及添加/删除支路端口。
RWA: Routing and Wavelength Assignment
RWA：路由和波长分配
Transparent Network: A Wavelength Switched Optical Network that does not contain regenerators or wavelength converters.
透明网络：不包含再生器或波长转换器的波长交换光网络。
Translucent Network: A Wavelength Switched Optical Network that is predominantly transparent but may also contain limited numbers of regenerators and/or wavelength converters.
半透明网络：一种波长交换光网络，主要是透明的，但也可能包含有限数量的再生器和/或波长转换器。
Tributary: A link or port on a WDM system that can carry significantly less than the full multiplex of wavelength signals found on the line side links/ports. Typical tributary ports are the add and drop ports on an ADM, and these support only a single wavelength channel.
支路：WDM系统上的链路或端口，其传输的波长信号远小于线路侧链路/端口上的波长信号的完全多路复用。典型的分支端口是ADM上的添加和删除端口，这些端口仅支持单个波长通道。
Wavelength Conversion/Converters: The process of converting an information-bearing optical signal centered at a given wavelength to information with "equivalent" content centered at a different wavelength. Wavelength conversion can be implemented via an optical-electronic-optical (OEO) process or via a strictly optical process.
波长转换/转换器：将以给定波长为中心的含有信息的光信号转换为以不同波长为中心的具有“等效”内容的信息的过程。波长转换可以通过光电光学（OEO）工艺或严格的光学工艺实现。
WDM: Wavelength Division Multiplexing
波分复用
Wavelength Switched Optical Networks (WSONs): WDM-based optical networks in which switching is performed selectively based on the center wavelength of an optical signal.
波长交换光网络（WSON）：基于WDM的光网络，其中根据光信号的中心波长选择性地执行交换。
There are deployment scenarios for WSONs where not all possible paths will yield suitable signal quality. There are multiple reasons; below is a non-exhaustive list of examples:
在无线传感器网络的部署场景中，并非所有可能的路径都能产生合适的信号质量。原因是多方面的,；以下是示例的非详尽列表：
o WSONs are evolving and are using multi-degree optical cross-connects in such a way that network topologies are changing from rings (and interconnected rings) to general mesh. Adding network equipment such as amplifiers or regenerators to ensure that all paths are feasible leads to an over-provisioned network. Indeed, even with over-provisioning, the network could still have some infeasible paths.
o 无线传感器网络正在发展，并且正在以这样一种方式使用多度光交叉连接，即网络拓扑正在从环形（和互连环形）转变为普通网状。添加网络设备，如放大器或再生器，以确保所有路径都是可行的，这将导致过度配置的网络。事实上，即使过度供应，网络仍可能有一些不可行的路径。
o Within a given network, the optical physical interface may change over the network's life; e.g., the optical interfaces might be upgraded to higher bitrates. Such changes could result in paths being unsuitable for the optical signal. Moreover, the optical physical interfaces are typically provisioned at various stages of the network's life span, as needed, by traffic demands.
o 在给定网络内，光物理接口可能在网络寿命期间发生变化；e、 例如，光学接口可以升级到更高的比特率。这种变化可能导致路径不适合光信号。此外，光物理接口通常根据业务需求在网络寿命的不同阶段提供。
o There are cases where a network is upgraded by adding new optical cross-connects to increase network flexibility. In such cases, existing paths will have their feasibility modified while new paths will need to have their feasibility assessed.
o 在某些情况下，通过添加新的光纤交叉连接来升级网络，以提高网络灵活性。在这种情况下，现有路径将修改其可行性，而新路径将需要评估其可行性。
o With the recent bitrate increases from 10G to 40G and 100G over a single wavelength, WSONs will likely be operated with a mix of wavelengths at different bitrates. This operational scenario will impose impairment constraints due to different physical behavior of different bitrates and associated modulation formats.
o 随着最近在单个波长上的比特率从10G增加到40G和100G，无线传感器网络很可能在不同比特率的波长混合下运行。由于不同比特率和相关调制格式的不同物理行为，此操作场景将施加损害约束。
Not having an impairment-aware control plane for such networks will require a more complex network design phase that needs to take into account the evolving network status in terms of equipment and traffic at the beginning stage. In addition, network operations such as path establishment will require significant pre-design via non-control-plane processes, resulting in significantly slower network provisioning.
没有针对此类网络的损伤感知控制平面将需要更复杂的网络设计阶段，该阶段需要在开始阶段考虑设备和流量方面不断变化的网络状态。此外，网络操作（如路径建立）将需要通过非控制平面过程进行大量的预设计，从而导致网络供应速度显著降低。
It should be highlighted that the impact of impairments and use in determination of path viability is not sufficiently well established for general applicability [G.680]; it will depend on network implementations. The use of an impairment-aware control plane, and the set of information distributed, will need to be evaluated on a case-by-case scenario.
应当强调的是，在确定路径生存能力时，损伤和使用的影响还不足以确定其普遍适用性[G.680]；这将取决于网络实现。损伤感知控制平面的使用和分布的信息集需要根据具体情况进行评估。
The basic criterion for path selection is whether one can successfully transmit the signal from a transmitter to a receiver within a prescribed error tolerance, usually specified as a maximum permissible BER. This generally depends on the nature of the signal transmitted between the sender and receiver and the nature of the communications channel between the sender and receiver. The optical path utilized (along with the wavelength) determines the communications channel.
路径选择的基本标准是能否在规定的误差容限（通常指定为最大允许误码率）内成功地将信号从发射机传输到接收机。这通常取决于发送方和接收方之间传输的信号的性质以及发送方和接收方之间通信信道的性质。所使用的光路（以及波长）决定了通信信道。
The optical impairments incurred by the signal along the fiber and at each optical network element along the path determine whether the BER performance or any other measure of signal quality can be met for a signal on a particular end-to-end path.
由沿光纤的信号以及在沿路径的每个光网络元件处产生的光损伤确定对于特定端到端路径上的信号是否可以满足BER性能或任何其他信号质量度量。
Impairment-aware path calculation also needs to take into account when regeneration is used along the path. [RFC6163] provides background on the concept of optical translucent networks that contain transparent elements and electro-optical elements such as OEO regenerations. In such networks, a generic light path can go through a number of regeneration points.
当沿路径使用再生时，还需要考虑损伤感知路径计算。[RFC6163]提供了包含透明元件和光电元件（如OEO再生）的光学半透明网络概念的背景知识。在这种网络中，普通光路可以通过许多再生点。
Regeneration points could happen for two reasons:
发生再生点可能有两个原因：
(i) Wavelength conversion is performed in order to assist RWA in avoiding wavelength blocking. This is the impairment-free case covered by [RFC6163].
(i) 执行波长转换以协助RWA避免波长阻塞。这是[RFC6163]所涵盖的无减值情况。
(ii) The optical signal without regeneration would be too degraded to meet end-to-end BER requirements. This is the case when RWA takes into consideration impairment estimation covered by this document.
（ii）未经再生的光信号将过于降级，无法满足端到端BER要求。当RWA考虑本文件所涵盖的减值估计时，就是这种情况。
In the latter case, an optical path can be seen as a set of transparent segments. The calculation of optical impairments needs to be reset at each regeneration point so each transparent segment will have its own impairment evaluation.
在后一种情况下，光路可视为一组透明段。光学损伤的计算需要在每个再生点重置，以便每个透明段都有自己的损伤评估。
+---+ +----+ +----+ +-----+ +----+ +---+
| I |----| N1 |---| N2 |-----| REG |-----| N3 |----| E |
+---+ +----+ +----+ +-----+ +----+ +---+
+---+ +----+ +----+ +-----+ +----+ +---+
| I |----| N1 |---| N2 |-----| REG |-----| N3 |----| E |
+---+ +----+ +----+ +-----+ +----+ +---+
|<----------------------------->|<-------------------->|
Segment 1 Segment 2
|<----------------------------->|<-------------------->|
Segment 1 Segment 2
Figure 1. Optical Path as a Set of Transparent Segments
图1。作为一组透明段的光路
For example, Figure 1 represents an optical path from node I to node E with a regeneration point, REG, in between. This is feasible from an impairment validation perspective if both segments (I, N1, N2, REG) and (REG, N3, E) are feasible.
例如，图1表示从节点I到节点E的光路，再生点REG位于两者之间。如果（I、N1、N2、REG）段和（REG、N3、E）段均可行，则从减值确认的角度来看，这是可行的。
This section examines the various optical network requirements and constraints under which an impairment-aware optical control plane may have to operate. These requirements and constraints motivate the IA-RWA architectural alternatives presented in Section 4.2. Different optical network contexts can be broken into two main criteria: (a) the accuracy required in the estimation of impairment effects and (b) the constraints on the impairment estimation computation and/or sharing of impairment information.
本节检查了各种光网络要求和约束，在这些要求和约束下，损伤感知光学控制平面可能必须运行。这些要求和约束促使IA-RWA架构备选方案出现在第4.2节中。不同的光网络环境可分为两个主要标准：（a）损伤效应估计所需的准确性和（b）损伤估计计算和/或共享损伤信息的限制。
A. No Concern for Impairments or Wavelength Continuity Constraints
A.不考虑损伤或波长连续性约束
This situation is covered by existing GMPLS with local wavelength (label) assignment.
这种情况由具有本地波长（标签）分配的现有GMPL覆盖。
B. No Concern for Impairments, but Wavelength Continuity Constraints
B.不考虑损伤，但考虑波长连续性约束
This situation is applicable to networks designed such that every possible path is valid for the signal types permitted on the network. In this case, impairments are only taken into account during network design; after that -- for example, during optical path computation -- they can be ignored. This is the case discussed in [RFC6163] where impairments may be ignored by the control plane and only optical parameters related to signal compatibility are considered.
这种情况适用于设计为每个可能路径对网络上允许的信号类型有效的网络。在这种情况下，仅在网络设计期间考虑损害；之后——例如，在光程计算过程中——它们可以被忽略。这是[RFC6163]中讨论的情况，其中控制平面可以忽略损伤，并且只考虑与信号兼容性相关的光学参数。
C. Approximated Impairment Estimation
C.近似减值估计
This situation is applicable to networks in which impairment effects need to be considered but where there is a sufficient margin such that impairment effects can be estimated via such approximation techniques as link budgets and dispersion [G.680] [G.Sup39]. The viability of optical paths for a particular class of signals can be estimated using well-defined approximation techniques [G.680] [G.Sup39]. This is generally known as the linear case, where only linear effects are taken into account. Note that adding or removing an optical signal on the path should not render any of the existing signals in the network non-viable. For example, one form of non-viability is the occurrence in existing links of transients of sufficient magnitude to impact the BER of existing signals.
这种情况适用于需要考虑减值影响的网络，但有足够的裕度，可以通过链路预算和离散度等近似技术估计减值影响[G.680][G.Sup39]。可以使用定义良好的近似技术[G.680][G.Sup39]估计特定类别信号的光路的可行性。这通常被称为线性情况，其中仅考虑线性效应。请注意，在路径上添加或删除光信号不应导致网络中的任何现有信号不可用。例如，非可行性的一种形式是在现有链路中发生足够大的瞬态，以影响现有信号的误码率。
Much work at ITU-T has gone into developing impairment models at this level and at more detailed levels. Impairment characterization of network elements may be used to calculate which paths are conformant with a specified BER for a particular signal type. In such a case, the impairment-aware (IA) path computation can be combined with the RWA process to permit more optimal IA-RWA computations. Note that the IA path computation may also take place in a separate entity, i.e., a PCE.
ITU-T在这一层面和更详细层面上开展了大量工作，以开发减值模型。网络元件的损伤表征可用于计算哪些路径符合特定信号类型的指定BER。在这种情况下，损伤感知（IA）路径计算可与RWA过程相结合，以允许更优化的IA-RWA计算。注意，IA路径计算也可以在单独的实体（即PCE）中进行。
D. Accurate Impairment Computation
D.准确的减值计算
This situation is applicable to networks in which impairment effects must be more accurately computed. For these networks, a full computation and evaluation of the impact to any existing paths need to be performed prior to the addition of a new path. Currently, no impairment models are available from ITU-T, and this scenario is outside the scope of this document.
这种情况适用于必须更准确地计算减值影响的网络。对于这些网络，在添加新路径之前，需要对任何现有路径的影响进行全面计算和评估。目前，ITU-T没有可用的减值模型，该场景不在本文档的范围内。
In GMPLS, information used for path computation is standardized for distribution amongst the elements participating in the control plane, and any appropriately equipped PCE can perform path computation. For optical systems, this may not be possible. This is typically due to only portions of an optical system being subject to standardization. In ITU-T Recommendations [G.698.1] and [G.698.2], which specify single-channel interfaces to multi-channel DWDM systems, only the single-channel interfaces (transmit and receive) are specified, while the multi-channel links are not standardized. These DWDM links are referred to as "black links", since their details are not generally available. However, note that the overall impact of a black link at the single-channel interface points is limited by [G.698.1] and [G.698.2].
在GMPLS中，用于路径计算的信息被标准化，以便在参与控制平面的元素之间分配，并且任何适当配备的PCE都可以执行路径计算。对于光学系统，这可能是不可能的。这通常是由于只有光学系统的一部分需要标准化。ITU-T建议[G.698.1]和[G.698.2]规定了多信道DWDM系统的单信道接口，其中仅规定了单信道接口（发送和接收），而多信道链路未标准化。这些DWDM链路被称为“黑链路”，因为它们的详细信息通常不可用。但是，请注意，单通道接口点处黑色链路的总体影响受到[G.698.1]和[G.698.2]的限制。
Typically, a vendor might use proprietary impairment models for DWDM spans in order to estimate the validity of optical paths. For example, models of optical nonlinearities are not currently standardized. Vendors may also choose not to publish impairment details for links or a set of network elements, in order not to divulge their optical system designs.
通常，供应商可能会对DWDM跨度使用专有的损伤模型，以估计光路的有效性。例如，光学非线性模型目前尚未标准化。供应商也可以选择不公布链路或一组网络元件的损坏详细信息，以免泄露其光学系统设计。
In general, the impairment estimation/validation of an optical path for optical networks with black links in the path could not be performed by a general-purpose IA computation entity, since it would not have access to or understand the black-link impairment parameters. However, impairment estimation (optical path validation) could be performed by a vendor-specific IA computation entity. Such a vendor-specific IA computation entity could utilize standardized impairment information imported from other network elements in these proprietary computations.
一般来说，由于通用IA计算实体无法访问或理解黑链路损伤参数，因此无法对路径中具有黑链路的光网络的光路径进行损伤估计/验证。然而，损伤估计（光路验证）可由供应商特定的IA计算实体执行。此类特定于供应商的IA计算实体可在这些专有计算中利用从其他网络元件导入的标准化减值信息。
In the following, the term "black links" will be used to describe these computation and information-sharing constraints in optical networks. From the control plane perspective, the following options are considered:
在下文中，术语“黑链路”将用于描述光网络中的这些计算和信息共享约束。从控制平面的角度来看，将考虑以下选项：
1. The authority in control of the black links can furnish a list of all viable paths between all viable node pairs to a computation entity. This information would be particularly useful as an input to RWA optimization to be performed by another computation entity. The difficulty here is that such a list of paths, along with any wavelength constraints, could get unmanageably large as the size of the network increases.
1. 控制黑链接的机构可以向计算实体提供所有可行节点对之间所有可行路径的列表。该信息作为将由另一计算实体执行的RWA优化的输入特别有用。这里的困难在于，随着网络规模的增加，这样的路径列表以及任何波长限制都可能变得难以管理。
2. The authority in control of the black links could provide a PCE-like entity a list of viable paths/wavelengths between two requested nodes. This is useful as an input to RWA optimizations and can reduce the scaling issue previously mentioned. Such a PCE-like entity would not need to perform a full RWA computation; i.e., it would not need to take into account current wavelength availability on links. Such an approach may require PCEP extensions for both the request and response information.
2. 控制黑链路的机构可以向类似PCE的实体提供两个请求节点之间的可行路径/波长列表。这对于RWA优化非常有用，可以减少前面提到的扩展问题。此类PCE类实体无需执行完整的RWA计算；i、 例如，它不需要考虑链路上当前的波长可用性。这种方法可能需要对请求和响应信息进行PCEP扩展。
3. The authority in control of the black links provides a PCE that performs full IA-RWA services. The difficulty here is that this option requires the one authority to also become the sole source of all RWA optimization algorithms.
3. 控制黑链接的机构提供一个PCE，该PCE执行完整的IA-RWA服务。这里的困难在于，该选项要求唯一的权威机构也成为所有RWA优化算法的唯一来源。
In all of the above cases, it would be the responsibility of the authority in control of the black links to import the shared impairment information from the other NEs via the control plane or other means as necessary.
在上述所有情况下，控制黑链接的机构有责任通过控制平面或其他必要方式从其他网元导入共享减值信息。
The impairment estimation process can be modeled through the following functional blocks. These blocks are independent of any control plane architecture; that is, they can be implemented by the same or by different control plane functions, as detailed in the following sections.
减值估计过程可通过以下功能块建模。这些块独立于任何控制平面架构；也就是说，它们可以通过相同或不同的控制平面功能来实现，详见以下章节。
+-----------------+
+------------+ +-----------+ | +------------+ |
| | | | | | | |
| Optical | | Optical | | | Optical | |
| Interface |------->| Impairment|--->| | Channel | |
| (Transmit/ | | Path | | | Estimation | |
| Receive) | | | | | | |
+------------+ +-----------+ | +------------+ |
| || |
| || |
| Estimation |
| || |
| \/ |
| +------------+ |
| | BER/ | |
| | Q Factor | |
| +------------+ |
+-----------------+
+-----------------+
+------------+ +-----------+ | +------------+ |
| | | | | | | |
| Optical | | Optical | | | Optical | |
| Interface |------->| Impairment|--->| | Channel | |
| (Transmit/ | | Path | | | Estimation | |
| Receive) | | | | | | |
+------------+ +-----------+ | +------------+ |
| || |
| || |
| Estimation |
| || |
| \/ |
| +------------+ |
| | BER/ | |
| | Q Factor | |
| +------------+ |
+-----------------+
Starting from the functional block on the left, the optical interface represents where the optical signal is transmitted or received and defines the properties at the path endpoints. Even the impairment-free case, such as scenario B in Section 4.1.1, needs to consider a minimum set of interface characteristics. In such a case, only a few parameters used to assess the signal compatibility will be taken into account (see [RFC6163]). For the impairment-aware case, these parameters may be sufficient or not, depending on the accepted level of approximation (scenarios C and D). This functional block highlights the need to consider a set of interface parameters during the impairment validation process.
从左侧的功能块开始，光接口表示光信号的传输或接收位置，并定义路径端点处的属性。即使是无损伤的情况，如4.1.1节中的方案B，也需要考虑最小的接口特性集合。在这种情况下，仅考虑用于评估信号兼容性的几个参数（见[RFC6163]）。对于减值感知情况，这些参数可能足够或不够，取决于可接受的近似水平（场景C和D）。这个功能块强调了在减值验证过程中考虑一组接口参数的必要性。
The "Optical Impairment Path" block represents the types of impairments affecting a wavelength as it traverses the networks through links and nodes. In the case of a network where there are no impairments (scenario A), this block will not be present. Otherwise, this function must be implemented in some way via the control plane. Architectural alternatives to accomplish this are provided in Section 4.2. This block implementation (e.g., through routing, signaling, or a PCE) may influence the way the control plane distributes impairment information within the network.
“光损伤路径”块表示当波长通过链路和节点穿过网络时影响波长的损伤类型。如果网络没有损伤（场景a），则不会出现此块。否则，必须通过控制平面以某种方式实现此功能。第4.2节提供了实现这一点的架构备选方案。该块实现（例如，通过路由、信令或PCE）可影响控制平面在网络内分发损伤信息的方式。
The last block implements the decision function for path feasibility. Depending on the IA level of approximation, this function can be more or less complex. For example, in the case of no IA approximation, only the signal class compatibility will be verified. In addition to a feasible/not-feasible result, it may be worthwhile for decision functions to consider the case in which paths would likely be feasible within some degree of confidence. The optical impairments
最后一个模块实现了路径可行性的决策函数。根据IA近似级别的不同，此函数可能或多或少复杂。例如，在没有IA近似的情况下，将只验证信号类兼容性。除了一个可行的/不可行的结果，决策函数可能是值得考虑的情况下，路径可能是可行的，在一定程度的信心。光学损伤
are usually not fixed values, as they may vary within ranges of values according to the approach taken in the physical modeling (worst-case, statistical, or based on typical values). For example, the utilization of the worst-case value for each parameter within the impairment validation process may lead to marking some paths as not feasible, while they are very likely to be, in reality, feasible.
通常不是固定值，因为它们可能根据物理建模中采用的方法（最坏情况、统计或基于典型值）在值的范围内变化。例如，在减值验证过程中使用每个参数的最坏情况值可能会导致将某些路径标记为不可行，而实际上它们很可能是可行的。
From a control plane point of view, optical impairments are additional constraints to the impairment-free RWA process described in [RFC6163]. In IA-RWA, there are conceptually three general classes of processes to be considered: Routing (R), Wavelength Assignment (WA), and Impairment Validation (IV), i.e., estimation.
从控制平面的角度来看，光学损伤是[RFC6163]中描述的无损伤RWA过程的附加约束。在IA-RWA中，从概念上讲，有三类过程需要考虑：路由（R）、波长分配（WA）和损伤验证（IV），即估计。
Impairment validation may come in many forms and may be invoked at different levels of detail in the IA-RWA process. All of the variations of impairment validation discussed in this section are based on scenario C ("Approximated Impairment Estimation") as discussed in Section 4.1.1. From a process point of view, the following three forms of impairment validation will be considered:
减值确认可能有多种形式，并可在IA-RWA流程中的不同详细级别进行调用。本节讨论的所有减值确认变化均基于第4.1.1节讨论的情景C（“近似减值估计”）。从流程角度来看，将考虑以下三种形式的减值确认：
o IV-Candidates
o 四候选人
In this case, an IV process furnishes a set of paths between two nodes along with any wavelength restrictions, such that the paths are valid with respect to optical impairments. These paths and wavelengths may not actually be available in the network, due to its current usage state. This set of paths could be returned in response to a request for a set of at most K valid paths between two specified nodes. Note that such a process never directly discloses optical impairment information. Note also that this case includes any paths between the source and destination that may have been "pre-validated".
在这种情况下，IV过程在两个节点之间提供一组路径以及任何波长限制，使得路径对于光学损伤有效。由于当前的使用状态，这些路径和波长在网络中可能实际上不可用。在两个指定节点之间请求一组最多K个有效路径时，可以返回这组路径。注意，这样的过程从不直接公开光学损伤信息。还要注意，这种情况包括源和目标之间可能已“预验证”的任何路径。
In this case, the control plane simply makes use of candidate paths but does not have any optical impairment information. Another option is when the path validity is assessed within the control plane. The following cases highlight this situation.
在这种情况下，控制平面仅使用候选路径，但不具有任何光学损伤信息。另一种选择是在控制平面内评估路径有效性。以下案例突出了这种情况。
o IV-Approximate Verification
o 四近似验证
Here, approximation methods are used to estimate the impairments experienced by a signal. Impairments are typically approximated by linear and/or statistical characteristics of individual or combined components and fibers along the signal path.
这里，近似方法用于估计信号所经历的损伤。损伤通常通过沿信号路径的单个或组合组件和光纤的线性和/或统计特征来近似。
o IV-Detailed Verification
o 四详细核查
In this case, an IV process is given a particular path and wavelength through an optical network and is asked to verify whether the overall quality objectives for the signal over this path can be met. Note that such a process never directly discloses optical impairment information.
在这种情况下，通过光网络为IV过程提供特定的路径和波长，并要求其验证该路径上的信号的总体质量目标是否能够满足。注意，这样的过程从不直接公开光学损伤信息。
The next two cases refer to the way an impairment validation computation can be performed from a decision-making point of view.
接下来的两种情况是指从决策角度执行减值确认计算的方式。
o IV-Centralized
o 四集中
In this case, impairments to a path are computed at a single entity. The information concerning impairments, however, may still be gathered from network elements. Depending on how information is gathered, this may put additional requirements on routing protocols. This topic will be detailed in later sections.
在这种情况下，在单个实体上计算对路径的损害。然而，关于损伤的信息仍然可以从网络元素中收集。根据收集信息的方式，这可能会对路由协议提出额外的要求。本主题将在后面的章节中详细介绍。
o IV-Distributed
o 四、分发
In the distributed IV process, approximate degradation measures such as OSNR, dispersion, DGD, etc., may be accumulated along the path via signaling. Each node on the path may already perform some part of the impairment computation (i.e., distributed). When the accumulated measures reach the destination node, a decision on the impairment validity of the path can be made. Note that such a process would entail revealing an individual network element's impairment information, but it does not generally require distributing optical parameters to the entire network.
在分布式IV过程中，诸如OSNR、色散、DGD等的近似退化度量可经由信令沿路径累积。路径上的每个节点可能已经执行了损伤计算的某些部分（即分布式）。当累积的度量到达目的地节点时，可以对路径的有效性作出决定。注意，这样的过程将需要揭示单个网络元件的损伤信息，但是它通常不需要向整个网络分发光学参数。
The control plane must not preclude the possibility of concurrently performing one or all of the above cases in the same network. For example, there could be cases where a certain number of paths are already pre-validated (IV-Candidates), so the control plane may set up one of those paths without requesting any impairment validation procedure. On the same network, however, the control plane may compute a path outside the set of IV-Candidates for which an impairment evaluation can be necessary.
控制平面不得排除在同一网络中同时执行上述一种或所有情况的可能性。例如，可能存在特定数量的路径已经预先验证（IV候选）的情况，因此控制平面可以设置其中一条路径，而无需请求任何损伤验证程序。然而，在同一网络上，控制平面可计算可能需要进行损伤评估的IV候选集合之外的路径。
The following subsections present three major classes of IA-RWA path computation architectures and review some of their respective advantages and disadvantages.
以下小节介绍了IA-RWA路径计算体系结构的三大类，并回顾了它们各自的优缺点。
From the point of view of optimality, reasonably good IA-RWA solutions can be achieved if the PCE can conceptually/algorithmically combine the processes of routing, wavelength assignment, and impairment validation.
从最优性的角度来看，如果PCE能够在概念上/算法上结合路由、波长分配和损伤验证过程，则可以获得相当好的IA-RWA解决方案。
Such a combination can take place if the PCE is given (a) the impairment-free WSON information as discussed in [RFC6163] and (b) impairment information to validate potential paths.
如果给PCE（a）如[RFC6163]中所述的无损伤WSON信息和（b）用于验证潜在路径的损伤信息，则可以进行这种组合。
Separating the processes of routing, WA, and/or IV can reduce the need for the sharing of different types of information used in path computation. This was discussed for routing, separate from WA, in [RFC6163]. In addition, as was discussed in Section 4.1.2, some impairment information may not be shared, and this may lead to the need to separate IV from RWA. In addition, if IV needs to be done at a high level of precision, it may be advantageous to offload this computation to a specialized server.
分离路由、WA和/或IV的过程可以减少共享路径计算中使用的不同类型信息的需要。[RFC6163]中讨论了这一点，并将其与WA分开。此外，如第4.1.2节所述，某些减值信息可能无法共享，这可能导致需要将IV与RWA分开。此外，如果需要以高精度执行IV，则将此计算卸载到专用服务器可能是有利的。
The following conceptual architectures belong in this general category:
以下概念体系结构属于此一般类别：
o R + WA + IV separate routing, wavelength assignment, and impairment validation.
o R+WA+IV独立路由、波长分配和损伤验证。
o R + (WA & IV) routing separate from a combined wavelength assignment and impairment validation process. Note that impairment validation is typically wavelength dependent. Hence, combining WA with IV can lead to improved efficiency.
o R+（WA和IV）路由独立于组合波长分配和损伤验证过程。注意，损伤验证通常取决于波长。因此，将WA与IV结合可以提高效率。
o (RWA) + IV combined routing and wavelength assignment with a separate impairment validation process.
o （RWA）+IV将路由和波长分配与单独的减值验证过程相结合。
Note that the IV process may come before or after the RWA processes. If RWA comes first, then IV is just rendering a yes/no decision on the selected path and wavelength. If IV comes first, it would need to furnish a list of possible (valid with respect to impairments) routes and wavelengths to the RWA processes.
请注意，IV流程可能在RWA流程之前或之后。如果RWA首先出现，则IV只是在所选路径和波长上呈现是/否决策。如果IV排在第一位，则需要向RWA流程提供一份可能的（对损害有效的）路由和波长列表。
In the non-impairment RWA situation [RFC6163], it was shown that a distributed WA process carried out via signaling can eliminate the need to distribute wavelength availability information via an interior gateway protocol (IGP). A similar approach can allow for the distributed computation of impairment effects and avoid the need to distribute impairment characteristics of network elements and links by routing protocols or by other means. Therefore, the following conceptual options belong to this category:
在非损伤RWA情况下[RFC6163]，通过信令执行的分布式WA过程可以消除通过内部网关协议（IGP）分发波长可用性信息的需要。类似的方法可以允许损伤效应的分布式计算，并避免需要通过路由协议或其他方式来分布网络元件和链路的损伤特征。因此，以下概念选项属于这一类别：
o RWA + D(IV) combined routing and wavelength assignment and distributed impairment validation.
o RWA+D（IV）结合路由和波长分配以及分布式损伤验证。
o R + D(WA & IV) routing separate from a distributed wavelength assignment and impairment validation process.
o R+D（WA&IV）路由独立于分布式波长分配和损伤验证过程。
Distributed impairment validation for a prescribed network path requires that the effects of impairments be calculated by approximate models with cumulative quality measures such as those given in [G.680]. The protocol encoding of the impairment-related information from [G.680] would need to be agreed upon.
规定网络路径的分布式损伤验证要求通过具有累积质量度量的近似模型来计算损伤的影响，如[G.680]中给出的模型。需要商定[G.680]中减值相关信息的协议编码。
If distributed WA is being done at the same time as distributed IV, then it is necessary to accumulate impairment-related information for all wavelengths that could be used. The amount of information is reduced somewhat as potential wavelengths are discovered to be in use but could be a significant burden for lightly loaded networks with high channel counts.
如果分布式WA与分布式IV同时进行，则有必要为可使用的所有波长积累损伤相关信息。当发现潜在波长正在使用时，信息量会有所减少，但对于具有高信道数的轻负载网络来说，这可能是一个巨大的负担。
Figure 2 shows process flows for the three main architectural alternatives to IA-RWA that apply when approximate impairment validation is sufficient. Figure 3 shows process flows for the two main architectural alternatives that apply when detailed impairment verification is required.
图2显示了IA-RWA的三个主要架构备选方案的流程，这些备选方案在近似减值验证充分时适用。图3显示了当需要进行详细的减值验证时适用的两个主要架构备选方案的流程。
+-----------------------------------+
| +--+ +-------+ +--+ |
| |IV| |Routing| |WA| |
| +--+ +-------+ +--+ |
| |
| Combined Processes |
+-----------------------------------+
(a)
+-----------------------------------+
| +--+ +-------+ +--+ |
| |IV| |Routing| |WA| |
| +--+ +-------+ +--+ |
| |
| Combined Processes |
+-----------------------------------+
(a)
+--------------+ +----------------------+
| +----------+ | | +-------+ +--+ |
| | IV | | | |Routing| |WA| |
| |Candidates| |----->| +-------+ +--+ |
| +----------+ | | Combined Processes |
+--------------+ +----------------------+
(b)
+--------------+ +----------------------+
| +----------+ | | +-------+ +--+ |
| | IV | | | |Routing| |WA| |
| |Candidates| |----->| +-------+ +--+ |
| +----------+ | | Combined Processes |
+--------------+ +----------------------+
(b)
+-----------+ +----------------------+
| +-------+ | | +--+ +--+ |
| |Routing| |------->| |WA| |IV| |
| +-------+ | | +--+ +--+ |
+-----------+ | Distributed Processes|
+----------------------+
(c)
+-----------+ +----------------------+
| +-------+ | | +--+ +--+ |
| |Routing| |------->| |WA| |IV| |
| +-------+ | | +--+ +--+ |
+-----------+ | Distributed Processes|
+----------------------+
(c)
Figure 2. Process Flows for the Three Main Approximate Impairment Architectural Alternatives
图2。三种主要架构备选方案的流程
The advantages, requirements, and suitability of these options are as follows:
这些选项的优点、要求和适用性如下：
o Combined IV & RWA process
o IV和RWA组合流程
This alternative combines RWA and IV within a single computation entity, enabling highest potential optimality and efficiency in IA-RWA. This alternative requires that the computation entity have impairment information as well as non-impairment RWA information. This alternative can be used with black links but would then need to be provided by the authority controlling the black links.
该方案将RWA和IV结合在一个计算实体内，实现IA-RWA中最高的潜在优化和效率。该备选方案要求计算实体具有减值信息以及非减值RWA信息。此替代方案可用于黑链接，但随后需要由控制黑链接的机构提供。
o IV-Candidates + RWA process
o IV候选人+RWA流程
This alternative allows separation of impairment information into two computation entities while still maintaining a high degree of potential optimality and efficiency in IA-RWA. The IV-Candidates process needs to have impairment information from all optical network elements, while the RWA process needs to have
该替代方案允许将减值信息分离为两个计算实体，同时仍保持IA-RWA中的高度潜在最优性和效率。IV候选进程需要具有来自所有光网络元件的损伤信息，而RWA进程需要具有
non-impairment RWA information from the network elements. This alternative can be used with black links, but the authority in control of the black links would need to provide the functionality of the IV-Candidates process. Note that this is still very useful, since the algorithmic areas of IV and RWA are very different and conducive to specialization.
来自网络元件的非减值RWA信息。此替代方案可用于黑色链接，但控制黑色链接的机构需要提供IV候选人流程的功能。请注意，这仍然非常有用，因为IV和RWA的算法区域非常不同，并且有利于专门化。
o Routing + Distributed WA and IV
o 路由+分布式WA和IV
In this alternative, a signaling protocol may be extended and leveraged in the wavelength assignment and impairment validation processes. Although this doesn't enable as high a potential degree of optimality as (a) or (b), it does not require distribution of either link wavelength usage or link/node impairment information. Note that this is most likely not suitable for black links.
在该替代方案中，可以在波长分配和损伤验证过程中扩展和利用信令协议。尽管这无法实现（a）或（b）那样高的潜在优化程度，但它不需要分发链路波长使用情况或链路/节点损坏信息。请注意，这很可能不适用于黑色链接。
+-----------------------------------+ +------------+
| +-----------+ +-------+ +--+ | | +--------+ |
| | IV | |Routing| |WA| | | | IV | |
| |Approximate| +-------+ +--+ |---->| |Detailed| |
| +-----------+ | | +--------+ |
| Combined Processes | | |
+-----------------------------------+ +------------+
(a)
+-----------------------------------+ +------------+
| +-----------+ +-------+ +--+ | | +--------+ |
| | IV | |Routing| |WA| | | | IV | |
| |Approximate| +-------+ +--+ |---->| |Detailed| |
| +-----------+ | | +--------+ |
| Combined Processes | | |
+-----------------------------------+ +------------+
(a)
+--------------+ +----------------------+ +------------+
| +----------+ | | +-------+ +--+ | | +--------+ |
| | IV | | | |Routing| |WA| |---->| | IV | |
| |Candidates| |----->| +-------+ +--+ | | |Detailed| |
| +----------+ | | Combined Processes | | +--------+ |
+--------------+ +----------------------+ | |
(b) +------------+
+--------------+ +----------------------+ +------------+
| +----------+ | | +-------+ +--+ | | +--------+ |
| | IV | | | |Routing| |WA| |---->| | IV | |
| |Candidates| |----->| +-------+ +--+ | | |Detailed| |
| +----------+ | | Combined Processes | | +--------+ |
+--------------+ +----------------------+ | |
(b) +------------+
Figure 3. Process Flows for the Two Main Detailed Impairment Validation Architectural Options
图3。两个主要详细减值确认架构选项的流程
The advantages, requirements, and suitability of these detailed validation options are as follows:
这些详细验证选项的优点、要求和适用性如下：
o Combined Approximate IV & RWA + Detailed-IV
o 组合近似IV和RWA+详细IV
This alternative combines RWA and approximate IV within a single computation entity, enabling the highest potential optimality and efficiency in IA-RWA while keeping a separate entity performing detailed impairment validation. In the case of black links, the authority controlling the black links would need to provide all functionality.
该备选方案将RWA和近似IV组合在一个计算实体内，在IA-RWA中实现最高的潜在最优性和效率，同时保持一个单独的实体执行详细的减值验证。在黑链接的情况下，控制黑链接的机构需要提供所有功能。
o IV-Candidates + RWA + Detailed-IV
o IV候选人+RWA+详细IV
This alternative allows separation of approximate impairment information into a computation entity while still maintaining a high degree of potential optimality and efficiency in IA-RWA; then, a separate computation entity performs detailed impairment validation. Note that detailed impairment estimation is not standardized.
该备选方案允许将近似减值信息分离到计算实体中，同时仍保持IA-RWA中的高度潜在最优性和效率；然后，一个单独的计算实体执行详细的减值验证。请注意，详细的减值估计未标准化。
The previous IA-RWA architectural alternatives and process flows make differing demands on a GMPLS/PCE-based control plane. This section discusses the use of (a) an impairment information model, (b) the PCE as computation entity assuming the various process roles and consequences for PCEP, (c) possible extensions to signaling, and (d) possible extensions to routing. This document is providing this evaluation to aid protocol solutions work. The protocol specifications may deviate from this assessment. The assessment of the impacts to the control plane for IA-RWA is summarized in Figure 4.
先前的IA-RWA体系结构备选方案和工艺流程对基于GMPLS/PCE的控制平面提出了不同的要求。本节讨论（a）减值信息模型的使用，（b）假设PCEP的各种过程角色和后果的PCE作为计算实体，（c）信令的可能扩展，以及（d）路由的可能扩展。本文件提供此评估以帮助协议解决方案的工作。协议规范可能会偏离此评估。图4总结了IA-RWA对控制平面的影响评估。
+--------------------+-----+-----+------------+---------+
| IA-RWA Option | PCE | Sig | Info Model | Routing |
+--------------------+-----+-----+------------+---------+
| Combined | Yes | No | Yes | Yes |
| IV & RWA | | | | |
+--------------------+-----+-----+------------+---------+
| IV-Candidates | Yes | No | Yes | Yes |
| + RWA | | | | |
+--------------------+-----+-----+------------+---------+
| Routing + | No | Yes | Yes | No |
|Distributed IV, RWA | | | | |
+--------------------+-----+-----+------------+---------+
+--------------------+-----+-----+------------+---------+
| IA-RWA Option | PCE | Sig | Info Model | Routing |
+--------------------+-----+-----+------------+---------+
| Combined | Yes | No | Yes | Yes |
| IV & RWA | | | | |
+--------------------+-----+-----+------------+---------+
| IV-Candidates | Yes | No | Yes | Yes |
| + RWA | | | | |
+--------------------+-----+-----+------------+---------+
| Routing + | No | Yes | Yes | No |
|Distributed IV, RWA | | | | |
+--------------------+-----+-----+------------+---------+
Figure 4. IA-RWA Architectural Options and Control Plane Impacts
图4。IA-RWA建筑方案和控制平面影响
As previously discussed, most IA-RWA scenarios rely, to a greater or lesser extent, on a common impairment information model. A number of ITU-T Recommendations cover both detailed and approximate impairment characteristics of fibers, a variety of devices, and a variety of subsystems. An impairment model that can be used as a guideline for optical network elements and assessment of path viability is given in [G.680].
如前所述，大多数IA-RWA情景或多或少地依赖于通用减值信息模型。许多ITU-T建议涵盖光纤、各种设备和各种子系统的详细和近似损伤特性。[G.680]中给出了可用作光网络元件和路径可行性评估指南的损伤模型。
It should be noted that the current version of [G.680] is limited to networks composed of a single WDM line system vendor combined with OADMs and/or PXCs from potentially multiple other vendors. This is known as "situation 1" and is shown in Figure 1-1 of [G.680]. It is planned in the future that [G.680] will include networks incorporating line systems from multiple vendors, as well as OADMs and/or PXCs from potentially multiple other vendors. This is known as "situation 2" and is shown in Figure 1-2 of [G.680].
应注意的是，[G.680]的当前版本仅限于由单个WDM线路系统供应商与可能来自多个其他供应商的OADM和/或PXC组成的网络。这被称为“情况1”，如[G.680]的图1-1所示。未来计划[G.680]将包括包含来自多个供应商的线路系统的网络，以及来自潜在多个其他供应商的OADM和/或PXC。这被称为“情况2”，如[G.680]的图1-2所示。
For the case of distributed IV, this would require more than an impairment information model. It would need a common impairment "computation" model. In the distributed IV case, one needs to standardize the accumulated impairment measures that will be conveyed and updated at each node. Section 9 of [G.680] provides guidance in this area, with specific formulas given for OSNR, residual dispersion, polarization mode dispersion/polarization-dependent loss, and effects of channel uniformity. However, specifics of what intermediate results are kept and in what form would need to be standardized for interoperability. As noted in [G.680], this information may possibly not be sufficient, and in such a case, the applicability would be network dependent.
对于分布式IV的情况，这需要的不仅仅是减值信息模型。它需要一个通用的减值“计算”模型。在分布式IV情况下，需要标准化将在每个节点传达和更新的累计减值措施。[G.680]第9节提供了该领域的指南，给出了OSNR、剩余色散、偏振模式色散/偏振相关损耗以及信道均匀性影响的具体公式。然而，保留哪些中间结果以及以何种形式保留的细节需要标准化以实现互操作性。如[G.680]所述，该信息可能不够充分，在这种情况下，适用性取决于网络。
Different approaches to path/wavelength impairment validation give rise to different demands placed on GMPLS routing protocols. In the case where approximate impairment information is used to validate paths, GMPLS routing may be used to distribute the impairment characteristics of the network elements and links based on the impairment information model previously discussed.
不同的路径/波长损伤验证方法对GMPLS路由协议提出了不同的要求。在使用近似损伤信息来验证路径的情况下，GMPLS路由可用于基于先前讨论的损伤信息模型来分布网络元件和链路的损伤特征。
Depending on the computational alternative, the routing protocol may need to advertise information necessary to the impairment validation process. This can potentially cause scalability issues, due to the high volume of data that need to be advertised. Such issues can be addressed by separating data that need to be advertised only rarely from data that need to be advertised more frequently, or by adopting other forms of awareness solutions as described in previous sections (e.g., a centralized and/or external IV entity).
根据计算备选方案，路由协议可能需要公布损伤验证过程所需的信息。由于需要公布的数据量很大，这可能会导致可伸缩性问题。这些问题可以通过将很少需要公布的数据与需要更频繁公布的数据分开来解决，或者通过采用前几节所述的其他形式的意识解决方案（例如，集中和/或外部IV实体）来解决。
In terms of scenario C in Section 4.1.1, the model defined by [G.680] will apply, and the routing protocol will need to gather information required for such computations.
就第4.1.1节中的场景C而言，[G.680]定义的模型将适用，路由协议将需要收集此类计算所需的信息。
In the case of distributed IV, no new demands would be placed on the routing protocol.
在分布式IV的情况下，不会对路由协议提出新的要求。
The largest impacts on signaling occur in the cases where distributed impairment validation is performed. In this case, it is necessary to accumulate impairment information, as previously discussed. In addition, since the characteristics of the signal itself, such as modulation type, can play a major role in the tolerance of impairments, this type of information will need to be implicitly or explicitly signaled so that an impairment validation decision can be made at the destination node.
对信号的最大影响发生在执行分布式减值验证的情况下。在这种情况下，如前所述，有必要积累减值信息。此外，由于信号本身的特性（例如调制类型）可以在损伤容限中起主要作用，因此需要隐式或显式地发送该类型的信息，以便可以在目的地节点作出损伤验证决策。
It remains for further study whether it may be beneficial to include additional information to a connection request, such as desired egress signal quality (defined in some appropriate sense) in non-distributed IV scenarios.
将附加信息包括到连接请求中是否有益，例如在非分布式IV场景中期望的出口信号质量（在某种适当意义上定义），有待进一步研究。
In Section 4.2, a number of computational architectural alternatives were given that could be used to meet the various requirements and constraints of Section 4.1. Here, the focus is on how these alternatives could be implemented via either a single PCE or a set of two or more cooperating PCEs, and the impacts on the PCEP. This document provides this evaluation to aid solutions work. The protocol specifications may deviate from this assessment.
在第4.2节中，给出了许多可用于满足第4.1节各种要求和约束的计算架构备选方案。这里，重点是如何通过单个PCE或一组两个或多个合作PCE实施这些替代方案，以及对PCEP的影响。本文档提供此评估以帮助解决方案的工作。协议规范可能会偏离此评估。
In this situation, shown in Figure 2(a), a single PCE performs all of the computations needed for IA-RWA.
在这种情况下，如图2（a）所示，单个PCE执行IA-RWA所需的所有计算。
o Traffic Engineering (TE) Database requirements: WSON topology and switching capabilities, WSON WDM link wavelength utilization, and WSON impairment information.
o 流量工程（TE）数据库要求：WSON拓扑和交换能力、WSON WDM链路波长利用率和WSON损伤信息。
o PCC to PCE Request Information: Signal characteristics/type, required quality, source node, and destination node.
o PCC到PCE请求信息：信号特征/类型、所需质量、源节点和目标节点。
o PCE to PCC Reply Information: If the computations completed successfully, then the PCE returns the path and its assigned wavelength. If the computations could not complete successfully, it would be potentially useful to know why. At a minimum, it is of interest to know if this was due to lack of wavelength availability, impairment considerations, or both. The information to be conveyed is for further study.
o PCE到PCC回复信息：如果计算成功完成，则PCE返回路径及其指定的波长。如果计算无法成功完成，了解原因可能会很有用。至少，有兴趣知道这是否是由于缺乏波长可用性、损害考虑或两者兼而有之。要传达的信息供进一步研究。
In this situation, as shown in Figure 2(b), two separate processes are involved in the IA-RWA computation. This requires two cooperating path computation entities: one for the IV-Candidates process and another for the RWA process. In addition, the overall process needs to be coordinated. This could be done with yet another PCE, or this functionality could be added to one of a number of previously defined entities. This later option requires that the RWA entity also act as the overall process coordinator. The roles, responsibilities, and information requirements for these two entities, when instantiated as PCEs, are given below.
在这种情况下，如图2（b）所示，IA-RWA计算涉及两个单独的过程。这需要两个协作路径计算实体：一个用于IV候选进程，另一个用于RWA进程。此外，需要协调整个进程。这可以通过另一个PCE完成，或者可以将此功能添加到先前定义的多个实体之一。后一种选择要求RWA实体同时担任整个流程协调人。这两个实体在实例化为PCE时的角色、职责和信息要求如下所示。
RWA and Coordinator PCE (RWA-Coord PCE):
RWA和协调PCE（RWA协调PCE）：
The RWA-Coord PCE is responsible for interacting with the PCC and for utilizing the IV-Candidates PCE as needed during RWA computations. In particular, it needs to know that it is to use the IV-Candidates PCE to obtain a potential set of routes and wavelengths.
RWA合作PCE负责与PCC互动，并在RWA计算期间根据需要利用IV候选PCE。特别是，需要知道的是，要使用IV候选PCE来获得一组潜在的路由和波长。
o TE Database requirements: WSON topology and switching capabilities, and WSON WDM link wavelength utilization (no impairment information).
o TE数据库要求：WSON拓扑和交换能力，以及WSON WDM链路波长利用率（无损坏信息）。
o PCC to RWA PCE request: same as in the combined case.
o PCC至RWA PCE请求：与合并案例相同。
o RWA PCE to PCC reply: same as in the combined case.
o RWA PCE对PCC的回复：与合并案例相同。
o RWA PCE to IV-Candidates PCE request: The RWA PCE asks for a set of at most K routes, along with acceptable wavelengths between nodes specified in the original PCC request.
o RWA PCE到IV候选PCE请求：RWA PCE请求一组最多K条路由，以及原始PCC请求中指定的节点之间的可接受波长。
o IV-Candidates PCE reply to RWA PCE: The IV-Candidates PCE returns a set of at most K routes, along with acceptable wavelengths between nodes specified in the RWA PCE request.
o IV候选者PCE回复RWA PCE：IV候选者PCE返回一组最多K条路由，以及RWA PCE请求中指定的节点之间的可接受波长。
IV-Candidates PCE:
四、PCE候选人：
The IV-Candidates PCE is responsible for impairment-aware path computation. It need not take into account current link wavelength utilization, but this is not prohibited. The IV-Candidates PCE is only required to interact with the RWA PCE as indicated above, and not the initiating PCC. Note: The RWA-Coord PCE is also a PCC with respect to the IV-Candidate.
IV候选PCE负责损伤感知路径计算。它不需要考虑当前链路波长利用率，但这并不是禁止的。IV候选者PCE只需与如上所述的RWA PCE交互，而不需要与发起PCC交互。注：RWA合作PCE也是IV候选人的PCC。
o TE Database requirements: WSON topology and switching capabilities, and WSON impairment information (no information link wavelength utilization required).
o TE数据库要求：WSON拓扑和交换能力，以及WSON损坏信息（不需要信息链路波长利用率）。
Figure 5 shows a sequence diagram for the possible interactions between the PCC, RWA-Coord PCE, and IV-Candidates PCE.
图5显示了PCC、RWA合作PCE和IV候选PCE之间可能相互作用的序列图。
+---+ +-------------+ +-----------------+
|PCC| |RWA-Coord PCE| |IV-Candidates PCE|
+-+-+ +------+------+ +---------+-------+
...___ (a) | |
| ````---...____ | |
| ```-->| |
| | |
| |--..___ (b) |
| | ```---...___ |
| | ```---->|
| | |
| | |
| | (c) ___...|
| | ___....---'''' |
| |<--'''' |
| | |
| | |
| (d) ___...| |
| ___....---''' | |
|<--''' | |
| | |
| | |
+---+ +-------------+ +-----------------+
|PCC| |RWA-Coord PCE| |IV-Candidates PCE|
+-+-+ +------+------+ +---------+-------+
...___ (a) | |
| ````---...____ | |
| ```-->| |
| | |
| |--..___ (b) |
| | ```---...___ |
| | ```---->|
| | |
| | |
| | (c) ___...|
| | ___....---'''' |
| |<--'''' |
| | |
| | |
| (d) ___...| |
| ___....---''' | |
|<--''' | |
| | |
| | |
Figure 5. Sequence Diagram for the Interactions between the PCC, RWA-Coord PCE, and IV-Candidates PCE
图5。PCC、RWA合作PCE和IV候选PCE之间相互作用的序列图
In step (a), the PCC requests a path that meets specified quality constraints between two nodes (A and Z) for a given signal represented either by a specific type or a general class with associated parameters. In step (b), the RWA-Coord PCE requests up to K candidate paths between nodes A and Z, and associated acceptable wavelengths. The term "K candidate paths" is associated with the k shortest path algorithm. It refers to an algorithm that finds multiple k short paths connecting the source and the destination in a graph allowing repeated vertices and edges in the paths. See details in [Eppstein].
在步骤（a）中，PCC针对由特定类型或具有相关参数的一般类表示的给定信号请求满足两个节点（a和Z）之间的指定质量约束的路径。在步骤（b）中，RWA协调PCE请求节点A和Z之间的多达K条候选路径以及相关联的可接受波长。术语“K个候选路径”与K个最短路径算法相关联。它指的是一种算法，该算法在一个图中找到连接源和目标的多个k短路径，允许路径中重复的顶点和边。有关详细信息，请参见[Eppstein]。
In step (c), the IV-Candidates PCE returns this list to the RWA-Coord PCE, which then uses this set of paths and wavelengths as input (e.g., a constraint) to its RWA computation. In step (d), the RWA-Coord PCE returns the overall IA-RWA computation results to the PCC.
在步骤（c）中，IV候选者PCE将该列表返回给RWA协调PCE，其随后使用该组路径和波长作为其RWA计算的输入（例如，约束）。在步骤（d）中，RWA协调PCE将IA-RWA的总体计算结果返回给PCC。
Previously, Figure 3 showed two cases where a separate detailed impairment validation process could be utilized. It is possible to place the detailed validation process into a separate PCE. Assuming that a different PCE assumes a coordinating role and interacts with the PCC, it is possible to keep the interactions with this separate IV-Detailed PCE very simple. Note that, from a message flow perspective, there is some inefficiency as a result of separating the IV-Candidates PCE from the IV-Detailed PCE in order to achieve a high degree of potential optimality.
之前，图3显示了两种情况，其中可以使用单独的详细减值验证流程。可以将详细的验证过程放入单独的PCE中。假设不同的PCE承担协调角色并与PCC互动，则可以使与该独立IV详细PCE的互动非常简单。请注意，从消息流的角度来看，将IV候选PCE与IV详细PCE分离以实现高度的潜在优化会导致一些低效。
IV-Detailed PCE:
四、详细的个人消费支出：
o TE Database requirements: The IV-Detailed PCE will need optical impairment information, WSON topology, and, possibly, WDM link wavelength usage information. This document puts no restrictions on the type of information that may be used in these computations.
o TE数据库要求：IV详细PCE将需要光学损伤信息、WSON拓扑，可能还需要WDM链路波长使用信息。本文件对这些计算中可能使用的信息类型没有限制。
o RWA-Coord PCE to IV-Detailed PCE request: The RWA-Coord PCE will furnish signal characteristics, quality requirements, path, and wavelength to the IV-Detailed PCE.
o RWA合作PCE至IV详细PCE请求：RWA合作PCE将向IV详细PCE提供信号特征、质量要求、路径和波长。
o IV-Detailed PCE to RWA-Coord PCE reply: The reply is essentially a yes/no decision as to whether the requirements could actually be met. In the case where the impairment validation fails, it would be helpful to convey information related to the cause or to quantify the failure, e.g., so that a judgment can be made regarding whether to try a different signal or adjust signal parameters.
o IV详细的私人股本公司对RWA合作私人股本公司的回复：该回复基本上是关于是否能够实际满足要求的是/否决定。在减值确认失败的情况下，传达与原因相关的信息或量化失败可能会有帮助，例如，这样可以判断是否尝试不同的信号或调整信号参数。
Figure 6 shows a sequence diagram for the interactions corresponding to the process shown in Figure 3(b). This involves interactions between the PCC, RWA PCE (acting as coordinator), IV-Candidates PCE, and IV-Detailed PCE.
图6显示了与图3（b）中所示流程对应的交互的序列图。这涉及PCC、RWA PCE（担任协调员）、IV候选人PCE和IV详细PCE之间的互动。
In step (a), the PCC requests a path that meets specified quality constraints between two nodes (A and Z) for a given signal represented either by a specific type or a general class with associated parameters. In step (b), the RWA-Coord PCE requests up to K candidate paths between nodes A and Z, and associated acceptable wavelengths. In step (c), the IV-Candidates PCE returns this list to
在步骤（a）中，PCC针对由特定类型或具有相关参数的一般类表示的给定信号请求满足两个节点（a和Z）之间的指定质量约束的路径。在步骤（b）中，RWA协调PCE请求节点A和Z之间的多达K条候选路径以及相关联的可接受波长。在步骤（c）中，IV候选者PCE将该列表返回给
the RWA-Coord PCE, which then uses this set of paths and wavelengths as input (e.g., a constraint) to its RWA computation. In step (d), the RWA-Coord PCE requests a detailed verification of the path and wavelength that it has computed. In step (e), the IV-Detailed PCE returns the results of the validation to the RWA-Coord PCE. Finally, in step (f), the RWA-Coord PCE returns the final results (either a path and wavelength, or a cause for the failure to compute a path and wavelength) to the PCC.
RWA Coord PCE，然后使用这组路径和波长作为其RWA计算的输入（例如，约束）。在步骤（d）中，RWA协调PCE请求对其计算的路径和波长进行详细验证。在步骤（e）中，IV详细PCE将验证结果返回给RWA合作PCE。最后，在步骤（f）中，RWA协调PCE向PCC返回最终结果（路径和波长，或计算路径和波长失败的原因）。
+----------+ +--------------+ +------------+
+---+ |RWA-Coord | |IV-Candidates | |IV-Detailed |
|PCC| | PCE | | PCE | | PCE |
+-+-+ +----+-----+ +------+-------+ +-----+------+
|.._ (a) | | |
| ``--.__ | | |
| `-->| | |
| | (b) | |
| |--....____ | |
| | ````---.>| |
| | | |
| | (c) __..-| |
| | __..---'' | |
| |<--'' | |
| | |
| |...._____ (d) |
| | `````-----....._____ |
| | `````----->|
| | |
| | (e) _____.....+
| | _____.....-----''''' |
| |<----''''' |
| (f) __.| |
| __.--'' |
|<-'' |
| |
+----------+ +--------------+ +------------+
+---+ |RWA-Coord | |IV-Candidates | |IV-Detailed |
|PCC| | PCE | | PCE | | PCE |
+-+-+ +----+-----+ +------+-------+ +-----+------+
|.._ (a) | | |
| ``--.__ | | |
| `-->| | |
| | (b) | |
| |--....____ | |
| | ````---.>| |
| | | |
| | (c) __..-| |
| | __..---'' | |
| |<--'' | |
| | |
| |...._____ (d) |
| | `````-----....._____ |
| | `````----->|
| | |
| | (e) _____.....+
| | _____.....-----''''' |
| |<----''''' |
| (f) __.| |
| __.--'' |
|<-'' |
| |
Figure 6. Sequence Diagram for the Interactions between the PCC, RWA-Coord PCE, IV-Candidates PCE, and IV-Detailed PCE
图6。PCC、RWA合作PCE、IV候选PCE和IV详细PCE之间相互作用的序列图
The issues concerning manageability and operations are beyond the scope of this document. The details of manageability and operational issues will have to be deferred to future protocol implementations.
有关可管理性和操作的问题超出了本文件的范围。可管理性和操作问题的细节必须推迟到未来的协议实现。
On a high level, the GMPLS-routing-based architecture discussed in Section 5.2 may have to deal with how to resolve potential scaling issues associated with disseminating a large amount of impairment characteristics of the network elements and links.
在高层次上，第5.2节中讨论的基于GMPLS路由的体系结构可能必须处理如何解决与传播大量网络元件和链路损伤特征相关的潜在扩展问题。
From a scaling point of view, the GMPLS-signaling-based architecture discussed in Section 5.3 would be more scalable than other alternatives, as this architecture would avoid the dissemination of a large amount of data to the networks. This benefit may come, however, at the expense of potentially inefficient use of network resources.
从可扩展性的角度来看，第5.3节中讨论的基于GMPLS信令的体系结构比其他备选方案更具可扩展性，因为该体系结构将避免向网络传播大量数据。然而，这种好处可能是以网络资源的潜在低效使用为代价的。
The PCE-based architectures discussed in Section 5.4 would have to consider operational complexity when implementing options that require the use of multiple PCE servers. The most serious case is the option discussed in Section 5.4.3 ("Approximate IA-RWA + Separate Detailed-IV"). The combined IV & RWA option (which was discussed in Section 5.4.1), on the other hand, is simpler to operate than are other alternatives, as one PCE server handles all functionality; however, this option may suffer from a heavy computation and processing burden compared to other alternatives.
在实现需要使用多个PCE服务器的选项时，在第5.4节中讨论的基于PCE的体系结构必须考虑操作复杂性。最严重的情况是第5.4.3节中讨论的选项（“近似IA-RWA+单独详细IV”）。另一方面，组合IV和RWA选项（在第5.4.1节中讨论）比其他备选方案更易于操作，因为一台PCE服务器处理所有功能；然而，与其他备选方案相比，该方案可能会承受沉重的计算和处理负担。
Interoperability may be a hurdle to overcome when trying to agree on some impairment parameters, especially those that are associated with the black links. This work has been in progress in ITU-T and needs some more time to mature.
在试图就一些损害参数达成一致意见时，互操作性可能是一个需要克服的障碍，特别是那个些和黑链接相关的参数。这项工作已经在ITU-T中进行，需要更多的时间来成熟。
This document discusses a number of control plane architectures that incorporate knowledge of impairments in optical networks. If such an architecture is put into use within a network, it will by its nature contain details of the physical characteristics of an optical network. Such information would need to be protected from intentional or unintentional disclosure, similar to other network information used within intra-domain protocols.
本文档讨论了许多控制平面架构，这些架构结合了光网络中的损伤知识。如果这种体系结构在网络中投入使用，它将从本质上包含光网络物理特性的细节。与域内协议中使用的其他网络信息类似，需要保护此类信息不被有意或无意泄露。
This document does not require changes to the security models within GMPLS and associated protocols. That is, the OSPF-TE, RSVP-TE, and PCEP security models could be operated unchanged. However, satisfying the requirements for impairment information dissemination using the existing protocols may significantly affect the loading of those protocols and may make the operation of the network more vulnerable to active attacks such as injections, impersonation, and man-in-the-middle attacks. Therefore, additional care may be required to ensure that the protocols are secure in the impairment-aware WSON environment.
本文件不要求更改GMPLS和相关协议中的安全模型。也就是说，OSPF-TE、RSVP-TE和PCEP安全模型可以保持不变。然而，使用现有协议满足损伤信息传播的要求可能显著影响这些协议的加载，并且可能使网络的操作更容易受到主动攻击，例如注入、模拟和中间人攻击。因此，可能需要额外注意以确保协议在感知损伤的WSON环境中是安全的。
Furthermore, the additional information distributed in order to address impairment information represents a disclosure of network capabilities that an operator may wish to keep private. Consideration should be given to securing this information. For a general discussion on MPLS- and GMPLS-related security issues, see the MPLS/GMPLS security framework [RFC5920] and, in particular, text detailing security issues when the control plane is physically separated from the data plane.
此外，为了解决损害信息而分发的附加信息表示对网络能力的披露，运营商可能希望将其保密。应考虑保护这些信息。有关MPLS和GMPLS相关安全问题的一般性讨论，请参阅MPLS/GMPLS安全框架[RFC5920]，特别是详细说明控制平面与数据平面物理分离时的安全问题的文本。
[G.680] ITU-T Recommendation G.680, "Physical transfer functions of optical network elements", July 2007.
[G.680]ITU-T建议G.680，“光网络元件的物理传输功能”，2007年7月。
[RFC3945] Mannie, E., Ed., "Generalized Multi-Protocol Label Switching (GMPLS) Architecture", RFC 3945, October 2004.
[RFC3945]Mannie，E.，Ed.“通用多协议标签交换（GMPLS）体系结构”，RFC 39452004年10月。
[RFC4655] Farrel, A., Vasseur, J.-P., and J. Ash, "A Path Computation Element (PCE)-Based Architecture", RFC 4655, August 2006.
[RFC4655]Farrel，A.，Vasseur，J.-P.，和J.Ash，“基于路径计算元素（PCE）的体系结构”，RFC 46552006年8月。
[Eppstein] Eppstein, D., "Finding the k shortest paths", 35th IEEE Symposium on Foundations of Computer Science, Santa Fe, pp. 154-165, 1994.
[Eppstein]Eppstein，D.，“寻找k条最短路径”，第35届IEEE计算机科学基础研讨会，圣达菲，第154-165页，1994年。
[G.698.1] ITU-T Recommendation G.698.1, "Multichannel DWDM applications with single-channel optical interfaces", November 2009.
[G.698.1]ITU-T建议G.698.1，“具有单通道光学接口的多通道DWDM应用”，2009年11月。
[G.698.2] ITU-T Recommendation G.698.2, "Amplified multichannel dense wavelength division multiplexing applications with single channel optical interfaces", November 2009.
[G.698.2]ITU-T建议G.698.2，“带单通道光学接口的放大多通道密集波分复用应用”，2009年11月。
[G.Sup39] ITU-T Series G Supplement 39, "Optical system design and engineering considerations", February 2006.
[G.Sup39]ITU-T系列G补编39，“光学系统设计和工程考虑”，2006年2月。
[RFC4054] Strand, J., Ed., and A. Chiu, Ed., "Impairments and Other Constraints on Optical Layer Routing", RFC 4054, May 2005.
[RFC4054]Strand，J.，Ed.，和A.Chiu，Ed.，“光学层路由的损伤和其他限制”，RFC 4054，2005年5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。
[RFC6163] Lee, Y., Ed., Bernstein, G., Ed., and W. Imajuku, "Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs)", RFC 6163, April 2011.
[RFC6163]Lee，Y.，Ed.，Bernstein，G.，Ed.，和W.Imajuku，“波长交换光网络（WSON）的GMPLS和路径计算元件（PCE）控制框架”，RFC 61632011年4月。
Ming Chen Huawei Technologies Co., Ltd. F3-5-B R&D Center, Huawei Base Bantian, Longgang District Shenzhen 518129 P.R. China
中国深圳市龙岗区华为基地坂田明晨华为技术有限公司F3-5-B研发中心邮编：518129
Phone: +86-755-28973237
EMail: mchen@huawei.com
Phone: +86-755-28973237
EMail: mchen@huawei.com
Rebecca Han Huawei Technologies Co., Ltd. F3-5-B R&D Center, Huawei Base Bantian, Longgang District Shenzhen 518129 P.R.China
Rebecca Han华为技术有限公司中国深圳市龙岗区华为基地坂田F3-5-B研发中心邮编：518129
Phone: +86-755-28973237
EMail: hanjianrui@huawei.com
Phone: +86-755-28973237
EMail: hanjianrui@huawei.com
Gabriele Galimberti Cisco Via Philips 12 20052 Monza Italy
Gabriele Galimberti Cisco通过飞利浦12 20052意大利蒙扎
Phone: +39 039 2091462
EMail: ggalimbe@cisco.com
Phone: +39 039 2091462
EMail: ggalimbe@cisco.com
Alberto Tanzi Cisco Via Philips 12 20052 Monza Italy
Alberto Tanzi Cisco Via Philips 12 20052意大利蒙扎
Phone: +39 039 2091469
EMail: altanzi@cisco.com
Phone: +39 039 2091469
EMail: altanzi@cisco.com
David Bianchi Cisco Via Philips 12 20052 Monza Italy
David Bianchi Cisco Via Philips 12 20052意大利蒙扎
EMail: davbianc@cisco.com
EMail: davbianc@cisco.com
Moustafa Kattan Cisco Dubai 500321 United Arab Emirates
穆斯塔法·卡坦思科迪拜500321阿拉伯联合酋长国
EMail: mkattan@cisco.com
EMail: mkattan@cisco.com
Dirk Schroetter Cisco
德克施罗德思科
EMail: dschroet@cisco.com
EMail: dschroet@cisco.com
Daniele Ceccarelli Ericsson Via A. Negrone 1/A Genova - Sestri Ponente Italy
Daniele Ceccarelli Ericsson通过A.Negrone 1/A Genova-意大利塞斯特里·波南特
EMail: daniele.ceccarelli@ericsson.com
EMail: daniele.ceccarelli@ericsson.com
Elisa Bellagamba Ericsson Farogatan 6 Kista 164 40 Sweden
Elisa Bellagamba Ericsson Farogatan 6 Kista 164 40瑞典
EMail: elisa.bellagamba@ericsson.com
EMail: elisa.bellagamba@ericsson.com
Diego Caviglia Ericsson Via A. Negrone 1/A Genova - Sestri Ponente Italy
Diego Caviglia Ericsson途经A.Negrone 1/A Genova-意大利塞斯特里·波南特
EMail: diego.caviglia@ericsson.com
EMail: diego.caviglia@ericsson.com
Authors' Addresses
作者地址
Young Lee (editor) Huawei Technologies 5340 Legacy Drive, Building 3 Plano, TX 75024 USA
Young Lee（编辑）美国德克萨斯州普莱诺3号楼华为技术5340 Legacy Drive 75024
Phone: (469) 277-5838 EMail: leeyoung@huawei.com
电话：（469）277-5838电子邮件：leeyoung@huawei.com
Greg M. Bernstein (editor) Grotto Networking Fremont, CA USA
Greg M.Bernstein（编辑）美国加利福尼亚州弗里蒙特Grotto Networking
Phone: (510) 573-2237 EMail: gregb@grotto-networking.com
电话：（510）573-2237电子邮件：gregb@grotto-网络
Dan Li Huawei Technologies Co., Ltd. F3-5-B R&D Center, Huawei Base Bantian, Longgang District Shenzhen 518129 P.R. China
中国深圳市龙岗区华为基地坂田丹丽华为技术有限公司F3-5-B研发中心邮编：518129
Phone: +86-755-28973237
EMail: danli@huawei.com
Phone: +86-755-28973237
EMail: danli@huawei.com
Giovanni Martinelli Cisco Via Philips 12 20052 Monza Italy
Giovanni Martinelli Cisco Via Philips 12 20052意大利蒙扎
Phone: +39 039 2092044
EMail: giomarti@cisco.com
Phone: +39 039 2092044
EMail: giomarti@cisco.com