BGP Extensions of SR Policy for Composite Candidate Path
draft-li-idr-sr-policy-composite-path-00

Document Type Active Internet-Draft (individual)
Authors Hao Li  , Mengxiao Chen  , Changwang Lin
Last updated 2021-02-02
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Network Working Group                                              H. Li
Internet-Draft                                                   M. Chen
Intended status: Standards Track                                  C. Lin
Expires: August 6, 2021                                              H3C
                                                        February 2, 2021

        BGP Extensions of SR Policy for Composite Candidate Path
                draft-li-idr-sr-policy-composite-path-00

Abstract

   Segment Routing is a source routing paradigm that explicitly
   indicates the forwarding path for packets at the ingress node.  An SR
   Policy is associated with one or more candidate paths.  A candidate
   path is either dynamic, explicit or composite.  This document defines
   extensions to BGP to distribute SR policies carrying composite
   candidate path information.  So that composite candidate paths can be
   installed when the SR policy is applied.

Status of This Memo

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   This Internet-Draft will expire on August 6, 2021.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   2
   3.  Constituent SR Policy Attributes in SR Policy . . . . . . . .   3
     3.1.  Constituent SR Policy Sub-TLV . . . . . . . . . . . . . .   4
   4.  Operations  . . . . . . . . . . . . . . . . . . . . . . . . .   5
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   5
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   5
   7.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .   6
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   6
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   6
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   Segment routing (SR) [RFC8402] is a source routing paradigm that
   explicitly indicates the forwarding path for packets at the ingress
   node.  The ingress node steers packets into a specific path according
   to the Segment Routing Policy (SR Policy) as defined in
   [I-D.ietf-spring-segment-routing-policy].  In order to distribute SR
   policies to the headend, [I-D.ietf-idr-segment-routing-te-policy]
   specifies a mechanism by using BGP.

   An SR Policy is associated with one or more candidate paths.  A
   composite candidate path acts as a container for grouping of SR
   Policies.  As described in section 2.2 in
   [I-D.ietf-spring-segment-routing-policy], the composite candidate
   path construct enables combination of SR Policies, each with explicit
   candidate paths and/or dynamic candidate paths with potentially
   different optimization objectives and constraints, for a load-
   balanced steering of packet flows over its constituent SR Policies.

   This document defines extensions to Border Gateway Protocol (BGP) to
   distribute SR policies carrying composite candidate path information.
   So that composite candidate paths can be installed when the SR policy
   is applied.

2.  Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP

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