SFC OAM for path consistency
draft-ao-sfc-oam-path-consistency-07

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SFC WG                                                             T. Ao
Internet-Draft                                    Individual contributor
Intended status: Standards Track                               G. Mirsky
Expires: June 3, 2020                                          ZTE Corp.
                                                                 Z. Chen
                                                           China Telecom
                                                                K. Leung
                                                            Cisco System
                                                        December 1, 2019

                      SFC OAM for path consistency
                  draft-ao-sfc-oam-path-consistency-07

Abstract

   Service Function Chain (SFC) defines an ordered set of service
   functions (SFs) to be applied to packets and/or frames and/or flows
   selected as a result of classification.  SFC Operation,
   Administration and Maintenance can monitor the continuity of the SFC,
   i.e., that all elements of the SFC are reachable to each other in the
   downstream direction.  But SFC OAM must support verification that the
   order of traversing these SFs corresponds to the state defined by the
   SFC control plane or orchestrator, the metric referred in this
   document as the path consistency of the SFC.  This document defines a
   new SFC active OAM method to support SFC consistency check, i.e.
   verification that all elements of the given SFC are being traversed
   in the expected order.

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
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   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on June 3, 2020.

Ao, et al.                Expires June 3, 2020                  [Page 1]
Internet-Draft        SFC OAM for path consistency         December 2019

Copyright Notice

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   document authors.  All rights reserved.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions used in this document . . . . . . . . . . . . . .   3
     2.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
     2.2.  Requirements Language . . . . . . . . . . . . . . . . . .   3
   3.  Consistency OAM: Theory of Operation  . . . . . . . . . . . .   3
     3.1.  COAM packet . . . . . . . . . . . . . . . . . . . . . . .   4
     3.2.  SFF Information Record TLV  . . . . . . . . . . . . . . .   4
     3.3.  SF Information Sub-TLV  . . . . . . . . . . . . . . . . .   5
     3.4.  SF Information Sub-TLV Construction . . . . . . . . . . .   6
       3.4.1.  Multiple SFs as hops of SFP . . . . . . . . . . . . .   6
       3.4.2.  Multiple SFs for load balance . . . . . . . . . . . .   7
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   7
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   8
     5.1.  COAM Message Types  . . . . . . . . . . . . . . . . . . .   8
     5.2.  SFF Information Record TLV Type . . . . . . . . . . . . .   8
     5.3.  SF Information Sub-TLV Type . . . . . . . . . . . . . . .   8
     5.4.  SF Identifier Types . . . . . . . . . . . . . . . . . . .   9
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   9
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   9
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .   9
     7.2.  Informational References  . . . . . . . . . . . . . . . .  10
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  10

1.  Introduction

   Service Function Chain (SFC) is a chain with a series of ordered
   Service Functions (SFs).  Service Function Path (SFP) is a path of a
   SFC.  SFC is described in detail in the SFC architecture document
   [RFC7665].  The SFs in the SFC are ordered and only when one SF