Controlled Return Path for Service Function Chain (SFC) OAM
draft-ao-sfc-oam-return-path-specified-08

Document Type Active Internet-Draft (individual)
Authors Greg Mirsky  , Ting Ao  , Zhonghua Chen  , Gyan Mishra 
Last updated 2021-01-19
Stream (None)
Intended RFC status (None)
Formats plain text xml pdf htmlized (tools) htmlized bibtex
Stream Stream state (No stream defined)
Consensus Boilerplate Unknown
RFC Editor Note (None)
IESG IESG state I-D Exists
Telechat date
Responsible AD (None)
Send notices to (None)
SFC WG                                                         G. Mirsky
Internet-Draft                                                 ZTE Corp.
Intended status: Standards Track                                   T. Ao
Expires: July 23, 2021                            Individual contributor
                                                                 Z. Chen
                                                           China Telecom
                                                               G. Mishra
                                                            Verizon Inc.
                                                        January 19, 2021

      Controlled Return Path for Service Function Chain (SFC) OAM
               draft-ao-sfc-oam-return-path-specified-08

Abstract

   This document defines an extension to the Service Function Chain
   (SFC) Operation, Administration and Maintenance (OAM) that enables
   control of the Echo Reply return path directing it over a Reverse
   Service Function Path.  Enforcing the specific return path can be
   used to verify the bidirectional connectivity of SFC and increase the
   robustness of SFC OAM.

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 July 23, 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

Mirsky, et al.            Expires July 23, 2021                 [Page 1]
Internet-Draft     Controlled Return Path for SFC OAM       January 2021

   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components 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
   2.  Conventions used in this document . . . . . . . . . . . . . .   3
     2.1.  Acronyms  . . . . . . . . . . . . . . . . . . . . . . . .   3
     2.2.  Requirements Language . . . . . . . . . . . . . . . . . .   3
   3.  Extension . . . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  SFC Reply Path TLV  . . . . . . . . . . . . . . . . . . . . .   4
   5.  Theory of Operation . . . . . . . . . . . . . . . . . . . . .   5
     5.1.  Bi-directional SFC Case . . . . . . . . . . . . . . . . .   6
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
     7.1.  SFC Return Path Type  . . . . . . . . . . . . . . . . . .   6
     7.2.  New Return Codes  . . . . . . . . . . . . . . . . . . . .   7
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   7
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   7
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   8
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   8

1.  Introduction

   While Service Function Chain (SFC) Echo Request, defined in
   [I-D.ietf-sfc-multi-layer-oam], always traverses the SFC it directed
   to, the corresponding Echo Reply is sent over IP network
   [I-D.ietf-sfc-multi-layer-oam].  There are scenarios when it is
   beneficial to direct the responder to use a path other than the IP
   network.  This document extends Service Function Chain (SFC)
   Operation, Administration and Maintenance (OAM) by enabling control
   of the Echo Reply return path to be directed over a Reply Service
   Function Path (SFP).  Such an extension is based on the analysis of
   SFC OAM, active OAM protocols, in particular, provided in [RFC8924].
   This document defines a new Type-Length-Value (TLV), Reply Service
   Function Path TLV, for Reply via Specified Path mode of SFC Echo
   Reply (Section 4).

   The Reply Service Function Path TLV can provide an efficient
   mechanism to test SFCs, such as bidirectional and hybrid SFC, as
   defined in Section 2.2 [RFC7665].  For example, it allows an operator
   to test both directions of the bidirectional or hybrid SFP with a
Show full document text