Link Management Protocol (LMP)
RFC 4204

Network Working Group                                       J. Lang, Ed.
Request for Comments: 4204                                   Sonos, Inc.
Category: Standards Track                                   October 2005

                     Link Management Protocol (LMP)

Status of This Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2005).

Abstract

   For scalability purposes, multiple data links can be combined to form
   a single traffic engineering (TE) link.  Furthermore, the management
   of TE links is not restricted to in-band messaging, but instead can
   be done using out-of-band techniques.  This document specifies a link
   management protocol (LMP) that runs between a pair of nodes and is
   used to manage TE links.  Specifically, LMP will be used to maintain
   control channel connectivity, verify the physical connectivity of the
   data links, correlate the link property information, suppress
   downstream alarms, and localize link failures for
   protection/restoration purposes in multiple kinds of networks.

Table of Contents

   1. Introduction ....................................................3
      1.1. Terminology ................................................5
   2. LMP Overview ....................................................6
   3. Control Channel Management ......................................8
      3.1. Parameter Negotiation ......................................9
      3.2. Hello Protocol ............................................10
   4. Link Property Correlation ......................................13
   5. Verifying Link Connectivity ....................................15
      5.1. Example of Link Connectivity Verification .................18
   6. Fault Management ...............................................19
      6.1. Fault Detection ...........................................20
      6.2. Fault Localization Procedure ..............................20
      6.3. Examples of Fault Localization ............................21

Lang                        Standards Track                     [Page 1]
RFC 4204             Link Management Protocol (LMP)         October 2005

      6.4. Channel Activation Indication .............................22
      6.5. Channel Deactivation Indication ...........................23
   7. Message_Id Usage ...............................................23
   8. Graceful Restart ...............................................24
   9. Addressing .....................................................25
   10. Exponential Back-off Procedures ...............................26
       10.1. Operation ...............................................26
       10.2. Retransmission Algorithm ................................27
   11. LMP Finite State Machines .....................................28
       11.1. Control Channel FSM .....................................28
       11.2. TE Link FSM .............................................32
       11.3. Data Link FSM ...........................................34
   12. LMP Message Formats ...........................................38
       12.1. Common Header ...........................................39
       12.2. LMP Object Format .......................................41
       12.3. Parameter Negotiation Messages ..........................42
       12.4. Hello Message (Msg Type = 4) ............................43
       12.5. Link Verification Messages ..............................43
       12.6. Link Summary Messages ...................................47
       12.7. Fault Management Messages ...............................49
   13. LMP Object Definitions ........................................50
       13.1. CCID (Control Channel ID) Class .........................50
       13.2. NODE_ID Class ...........................................51
       13.3. LINK_ID Class ...........................................52
       13.4. INTERFACE_ID Class ......................................53
       13.5. MESSAGE_ID Class ........................................54
       13.6. CONFIG Class ............................................55
       13.7. HELLO Class .............................................56
       13.8. BEGIN_VERIFY Class ......................................56
       13.9. BEGIN_VERIFY_ACK Class ..................................58
       13.10. VERIFY_ID Class ........................................59
       13.11. TE_LINK Class ..........................................59