Requirements for Generalized Multi-Protocol Label Switching (GMPLS) Routing for the Automatically Switched Optical Network (ASON)
RFC 4258

Network Working Group                                   D. Brungard, Ed.
Request for Comments: 4258                                           ATT
Category: Informational                                    November 2005

  Requirements for Generalized Multi-Protocol Label Switching (GMPLS)
     Routing for the Automatically Switched Optical Network (ASON)

Status of This Memo

   This memo provides information for the Internet community.  It does
   not specify an Internet standard of any kind.  Distribution of this
   memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2005).

Abstract

   The Generalized Multi-Protocol Label Switching (GMPLS) suite of
   protocols has been defined to control different switching
   technologies as well as 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).

   This document concentrates on the routing requirements placed on the
   GMPLS suite of protocols in order to support the capabilities and
   functionalities of an Automatically Switched Optical Network (ASON)
   as defined by the ITU-T.

Brungard, Ed.                Informational                      [Page 1]
RFC 4258                 GMPLS Routing for ASON            November 2005

Table of Contents

   1. Introduction ....................................................2
   2. Conventions Used in This Document ...............................4
   3. ASON Routing Architecture and Requirements ......................4
      3.1. Multiple Hierarchical Levels of ASON Routing Areas (RAs) ...5
      3.2. Hierarchical Routing Information Dissemination .............6
      3.3. Configuration ..............................................8
           3.3.1. Configuring the Multi-Level Hierarchy ...............8
           3.3.2. Configuring RC Adjacencies ..........................8
      3.4. Evolution ..................................................8
      3.5. Routing Attributes .........................................8
           3.5.1. Taxonomy of Routing Attributes ......................9
           3.5.2. Commonly Advertised Information .....................9
           3.5.3. Node Attributes ....................................10
           3.5.4. Link Attributes ....................................11
   4. Security Considerations ........................................12
   5. Conclusions ....................................................12
   6. Contributors ...................................................15
   7. Acknowledgements ...............................................15
   8. References .....................................................16
      8.1. Normative References ......................................16
      8.2. Informative References ....................................16

1.  Introduction

   The Generalized Multi-Protocol Label Switching (GMPLS) suite of
   protocols provides, among other capabilities, support for controlling
   different switching technologies.  These include support for
   requesting TDM connections utilizing SONET/SDH (see [T1.105] and
   [G.707], respectively) as well as Optical Transport Networks (OTNs,
   see [G.709]).  However, there are certain capabilities that are
   needed to support the ITU-T G.8080 control plane architecture for an
   Automatically Switched Optical Network (ASON).  Therefore, it is
   desirable to understand the corresponding requirements for the GMPLS
   protocol suite.  The ASON control plane architecture is defined in
   [G.8080]; ASON routing requirements are identified in [G.7715] and in
   [G.7715.1] for ASON link state protocols.  These Recommendations
   apply to all [G.805] layer networks (e.g., SDH and OTN), and provide
   protocol-neutral functional requirements and architecture.

   This document focuses on the routing requirements for the GMPLS suite
   of protocols to support the capabilities and functionality of ASON
   control planes.  This document summarizes the ASON requirements using
   ASON terminology.  This document does not address GMPLS applicability
   or GMPLS capabilities.  Any protocol (in particular, routing)

Brungard, Ed.                Informational                      [Page 2]
RFC 4258                 GMPLS Routing for ASON            November 2005

   applicability, design, or suggested extensions are strictly outside
   the scope of this document.  ASON (Routing) terminology sections are
   provided in Appendixes 1 and 2.

   The ASON routing architecture is based on the following assumptions:

   -  A network is subdivided based on operator decision and criteria
      (e.g., geography, administration, and/or technology); the network