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
Abstract
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.
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.
Lee, et al. Informational [Page 1]RFC 6566 Framework for Optical Impairments March 2012Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
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.
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.
Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
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Lee, et al. Informational [Page 2]RFC 6566 Framework for Optical Impairments March 2012Table of Contents
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
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