Controlled Return Path for Service Function Chain (SFC) OAM
draft-ao-sfc-oam-return-path-specified-06
SFC WG G. Mirsky
Internet-Draft ZTE Corp.
Intended status: Standards Track T. Ao
Expires: December 5, 2020 Individual contributor
Z. Chen
China Telecom
June 3, 2020
Controlled Return Path for Service Function Chain (SFC) OAM
draft-ao-sfc-oam-return-path-specified-06
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
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This Internet-Draft will expire on December 5, 2020.
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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. Extension . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. SFC Reply Path TLV . . . . . . . . . . . . . . . . . . . . . 4
5. Theory of Operation . . . . . . . . . . . . . . . . . . . . . 5
5.1. Bi-directional SFC Case . . . . . . . . . . . . . . . . . 5
6. Security Considerations . . . . . . . . . . . . . . . . . . . 5
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
7.1. SFC Return Path Type . . . . . . . . . . . . . . . . . . 6
7.2. New Return Codes . . . . . . . . . . . . . . . . . . . . 6
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
8.1. Normative References . . . . . . . . . . . . . . . . . . 6
8.2. Informative References . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
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 extension is based on the analysis of SFC
OAM, active OAM protocols in particular, provided in
[I-D.ietf-sfc-oam-framework]. 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
single SFC Echo Request/Echo Reply operation.
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