Signal Degrade Indication Used in Segment Routing over MPLS Network
draft-han-mpls-sdi-sr-00

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MPLS Working Group                                                L. Han
Internet-Draft                                              China Mobile
Intended status: Standards Track                                 F. Yang
Expires: January 14, 2021                            Huawei Technologies
                                                           July 13, 2020

  Signal Degrade Indication Used in Segment Routing over MPLS Network
                        draft-han-mpls-sdi-sr-00

Abstract

   This document describes the typical use cases for signal degrade
   indication used in SR over MPLS networks.  To satisfy the use cases
   and requirements of signal degrade indication, two extensions based
   on the BFD protocol and MPLS-TP OAM mechanisms are given
   respectively.

Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

Status of This Memo

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   This Internet-Draft will expire on January 14, 2021.

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   Copyright (c) 2020 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
   Provisions Relating to IETF Documents

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Overview  . . . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  BFD Indication Mechanism  . . . . . . . . . . . . . . . . . .   4
   5.  MPLS-TP Indication Mechanism  . . . . . . . . . . . . . . . .   5
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   6
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   7
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .   7
     9.2.  Informative References  . . . . . . . . . . . . . . . . .   7
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   The importance and necessity of signal degrade notification used in
   Segment Routing over MPLS networks is discussed in
   [I-D.yang-mpls-ps-sdi-sr].  When signal degrade is detected, this
   information could be extended by means of protocols to perform the
   performance monitoring, fault management, and trigger of protection
   mechanism etc.  Extensions on control plane, forwarding plane,
   management plane, and/or combination of any of them could be utilized
   to support the function of signal degrade indication.  This document
   provides two protocol extensions used in SR over MPLS networks, by
   specifying the encapsulations and behaviors in detail.

   In some of SR over MPLS networks, BFD [RFC5880] or enhanced SBFD
   [RFC7880] is widely utilized as the failure detection mechanism
   because of its' simplicity and efficiency characteristics.  The
   indication of signal degrade could be adopted as one of the reasons
   of BFD state changes.  In other SR over MPLS networks, MPLS-TP OAM
   [ITU-T G.8113.1] mechanisms are used instead of BFD or SBFD.  In this
   scenario, the extension based on the OAM PDU format is proposed in
   this document to support the signal degarde indication.

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2.  Terminology

   MPLS: Multiprotocol Label Switching

   SR: Segment Routing

   BFD: Bidirectional Forwarding Detection