Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs)
RFC 6163
Internet Engineering Task Force (IETF) Y. Lee, Ed.
Request for Comments: 6163 Huawei
Category: Informational G. Bernstein, Ed.
ISSN: 2070-1721 Grotto Networking
W. Imajuku
NTT
April 2011
Framework for GMPLS and Path Computation Element (PCE) Control
of Wavelength Switched Optical Networks (WSONs)
Abstract
This document provides a framework for applying Generalized Multi-
Protocol Label Switching (GMPLS) and the Path Computation Element
(PCE) architecture to the control of Wavelength Switched Optical
Networks (WSONs). In particular, it examines Routing and Wavelength
Assignment (RWA) of optical paths.
This document focuses on topological elements and path selection
constraints that are common across different WSON environments; as
such, it does not address optical impairments in any depth.
Status 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/rfc6163.
Lee, et al. Informational [Page 1]
RFC 6163 Wavelength Switched Optical Networks April 2011
Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction ....................................................4
2. Terminology .....................................................5
3. Wavelength Switched Optical Networks ............................6
3.1. WDM and CWDM Links .........................................6
3.2. Optical Transmitters and Receivers .........................8
3.3. Optical Signals in WSONs ...................................9
3.3.1. Optical Tributary Signals ..........................10
3.3.2. WSON Signal Characteristics ........................10
3.4. ROADMs, OXCs, Splitters, Combiners, and FOADMs ............11
3.4.1. Reconfigurable Optical Add/Drop
Multiplexers and OXCs ..............................11
3.4.2. Splitters ..........................................14
3.4.3. Combiners ..........................................15
3.4.4. Fixed Optical Add/Drop Multiplexers ................15
3.5. Electro-Optical Systems ...................................16
3.5.1. Regenerators .......................................16
3.5.2. OEO Switches .......................................19
3.6. Wavelength Converters .....................................19
3.6.1. Wavelength Converter Pool Modeling .................21
3.7. Characterizing Electro-Optical Network Elements ...........24
3.7.1. Input Constraints ..................................25
3.7.2. Output Constraints .................................25
3.7.3. Processing Capabilities ............................26
4. Routing and Wavelength Assignment and the Control Plane ........26
4.1. Architectural Approaches to RWA ...........................27
4.1.1. Combined RWA (R&WA) ................................27
4.1.2. Separated R and WA (R+WA) ..........................28
4.1.3. Routing and Distributed WA (R+DWA) .................28
4.2. Conveying Information Needed by RWA .......................29
Lee, et al. Informational [Page 2]
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