TPE-aided SPE-Protection
draft-wang-bess-tpe-aided-spe-protection-00

• Status
• IESG evaluation record
• IESG writeups
• Email expansions
• History

• Versions
• 00

BESS WG                                                          Y. Wang
Internet-Draft                                           ZTE Corporation
Intended status: Standards Track                         25 January 2021
Expires: 29 July 2021

                        TPE-aided SPE-Protection
              draft-wang-bess-tpe-aided-spe-protection-00

Abstract

   MPLS EVPN SPEs cannot make use of anycast MPLS tunnel (whose egress
   LSRs are two of these SPEs) because that the two SPEs will re-assign
   different EVPN labels for the same EVPN prefix.  It will be
   complicated to static-configure EVPN label for each EVPN prefix.  At
   the same time, the TPEs should advertise specified signalling to do
   egress node (TPE) protection.  This document specifies a egress node
   protection signalling from/among TPE nodes, and TPE (whether it is
   egress-protected or not) can help the SPEs to do egress protection on
   the basis of that signalling.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on 29 July 2021.

Copyright Notice

   Copyright (c) 2021 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 (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.  Code Components

Wang                      Expires 29 July 2021                  [Page 1]
Internet-Draft          TPE-aided SPE-Protection            January 2021

   extracted from this document must include Simplified BSD License text
   as described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Terminology and Acronyms  . . . . . . . . . . . . . . . .   2
   2.  Detailed Problem and Solution Requirement . . . . . . . . . .   4
     2.1.  Scenarios and Basic Settings  . . . . . . . . . . . . . .   4
       2.1.1.  Exception Case for Next Hop Validating  . . . . . . .   5
   3.  Control Plane Processing  . . . . . . . . . . . . . . . . . .   5
     3.1.  Downstream-CLS ID Extended Community  . . . . . . . . . .   5
     3.2.  TPE Procedures  . . . . . . . . . . . . . . . . . . . . .   6
     3.3.  SPE Procedures  . . . . . . . . . . . . . . . . . . . . .   7
       3.3.1.  Context-specific Label Swapping . . . . . . . . . . .   8
       3.3.2.  The Generating of Downstream-CLS ID EC on SPE . . . .   8
   4.  Protection Procedures . . . . . . . . . . . . . . . . . . . .   8
     4.1.  TPE Protection Procedures . . . . . . . . . . . . . . . .   8
     4.2.  SPE Protection Procedures . . . . . . . . . . . . . . . .   9
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   9
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   9
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  10
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  10
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  10
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  11
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .  11

1.  Introduction

   In section 2.5 and section 4.4 of
   [I-D.wang-bess-evpn-egress-protection], a MPLS egress protection
   signalling is defined.  The section 5.4 of
   [I-D.wang-bess-evpn-context-label] uses the same signalling to do
   egress protection for SPEs.  This draft put the two scenarios
   together, and describe all the unified signallings for the MPLS SPEs
   and TPEs.

   Note that the "egress" in "egress protection" means the egress LSR of
   the underlay LSP, not the egress LSR of the overlay LSP.  The SPEs
   are not the egress LSR of the overlay LSP, but they are the egress
   LSR of the underlay LSP.  So the anycast tunnel for SPEs is also
   egress protection tunnel for SPEs.

1.1.  Terminology and Acronyms

   This document uses the following acronyms and terms:

Wang                      Expires 29 July 2021                  [Page 2]
Internet-Draft          TPE-aided SPE-Protection            January 2021