A Transport Network View of the Link Management Protocol (LMP)
RFC 4394

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Network Working Group                                           D. Fedyk
Request for Comments: 4394                                 O. Aboul-Magd
Category: Informational                                  Nortel Networks
                                                             D. Brungard
                                                                    AT&T
                                                                 J. Lang
                                                             Sonos, Inc.
                                                        D. Papadimitriou
                                                                 Alcatel
                                                           February 2006

    A Transport Network View of the Link Management Protocol (LMP)

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 (2006).

Abstract

   The Link Management Protocol (LMP) has been developed as part of the
   Generalized MPLS (GMPLS) protocol suite to manage Traffic Engineering
   (TE) resources and links.  The GMPLS control plane (routing and
   signaling) uses TE links for establishing Label Switched Paths
   (LSPs).  This memo describes the relationship of the LMP procedures
   to 'discovery' as defined in the International Telecommunication
   Union (ITU-T), and ongoing ITU-T work.  This document provides an
   overview of LMP in the context of the ITU-T Automatically Switched
   Optical Networks (ASON) and transport network terminology and relates
   it to the ITU-T discovery work to promote a common understanding for
   progressing the work of IETF and ITU-T.

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RFC 4394             Transport Network View of LMP         February 2006

Table of Contents

   1. Introduction ....................................................2
   2. ASON Terminology and Abbreviations Related to Discovery .........3
      2.1. Terminology ................................................3
      2.2. Abbreviations ..............................................4
   3. Transport Network Architecture ..................................5
      3.1. G.8080 Discovery Framework .................................7
   4. Discovery Technologies ..........................................9
      4.1. Generalized Automatic Discovery Techniques G.7714 ..........9
      4.2. LMP and G.8080 Terminology Mapping .........................9
           4.2.1. TE Link Definition and Scope .......................12
      4.3. LMP and G.8080 Discovery Relationship .....................13
      4.4. Comparing LMP and G.8080 ..................................14
   5. Security Considerations ........................................15
   6. Informative References .........................................15
   7. Acknowledgements ...............................................16

1.  Introduction

   The GMPLS control plane consists of several building blocks as
   described in [RFC3945].  The building blocks include signaling,
   routing, and link management for establishing LSPs.  For scalability
   purposes, multiple physical resources can be combined to form a
   single TE link for the purposes of path computation and GMPLS control
   plane signaling.

   As manual provisioning and management of these links are impractical
   in large networks, LMP was specified to manage TE links.  Two
   mandatory management capabilities of LMP are control channel
   management and TE link property correlation.  Additional optional
   capabilities include verifying physical connectivity and fault
   management.  [LMP] defines the messages and procedures for GMPLS TE
   link management.  [LMP-TEST] defines SONET/SDH-specific messages and
   procedures for link verification.

   ITU-T Recommendation G.8080 Amendment 1 [G.8080] defines control
   plane discovery as two separate processes; one process occurs within
   the transport plane space and the other process occurs within the
   control plane space.

   The ITU-T has developed Recommendation G.7714, "Generalized automatic
   discovery techniques" [G.7714], defining the functional processes and
   information exchange related to transport plane discovery aspects,
   i.e., layer adjacency discovery and physical media adjacency
   discovery.  Specific methods and protocols are not defined in
   Recommendation G.7714.  ITU-T Recommendation G.7714.1, "Protocol for
   automatic discovery in SDH and OTN networks" [G.7714.1], defines a

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RFC 4394             Transport Network View of LMP         February 2006

   protocol and procedure for transport plane layer adjacency discovery
   (e.g., discovering the transport plane layer endpoint relationships