Explicit Congestion Notification (ECN) and Congestion Feedback Using the Network Service Header (NSH)
draft-ietf-sfc-nsh-ecn-support-04

Document Type Active Internet-Draft (sfc WG)
Authors Donald Eastlake  , Bob Briscoe  , Andy Malis 
Last updated 2020-12-06
Replaces draft-eastlake-sfc-nsh-ecn-support
Stream Internent Engineering Task Force (IETF)
Intended RFC status (None)
Formats plain text pdf htmlized (tools) htmlized bibtex
Stream WG state WG Document
Document shepherd No shepherd assigned
IESG IESG state I-D Exists
Consensus Boilerplate Unknown
Telechat date
Responsible AD (None)
Send notices to (None)
INTERNET-DRAFT                                           Donald Eastlake
Intended status: Proposed Standard                Futurewei Technologies
                                                             Bob Briscoe
                                                             Independent
                                                            Andrew Malis
                                                             Independent
Expires: June 5, 2021                                   December 6, 2020

     Explicit Congestion Notification (ECN) and Congestion Feedback
                 Using the Network Service Header (NSH)
                <draft-ietf-sfc-nsh-ecn-support-04.txt>

Abstract

   Explicit congestion notification (ECN) allows a forwarding element to
   notify downstream devices of the onset of congestion without having
   to drop packets. Coupled with a means to feed information about
   congestion back to upstream nodes, this can improve network
   efficiency through better congestion control, frequently without
   packet drops. This document specifies ECN and congestion feedback
   support within a Service Function Chaining (SFC) architecture domain
   through use of the Network Service Header (NSH, RFC 8300) and IP Flow
   Information Export (IPFIX,
   draft-ietf-tsvwg-tunnel-congestion-feedback).

Status of This Memo

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

   Distribution of this document is unlimited. Comments should be sent
   to the SFC Working Group mailing list <sfc@ietf.org> or to the
   authors.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-
   Drafts.

   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."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/1id-abstracts.html. The list of Internet-Draft
   Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.

D. Eastlake, B. Briscoe, & A. Malis                             [Page 1]
INTERNET-DRAFT                             NSH ECN & Congestion Feedback

Table of Contents

      1. Introduction............................................3
      1.1 NSH Background.........................................3
      1.2 ECN Background.........................................5
      1.3 Tunnel Congestion Feedback Background..................5
      1.4 Conventions Used in This Document......................7

      2. The NSH ECN Field.......................................8

      3. ECN Support in the NSH.................................10
      3.1 At The Ingress........................................11
      3.2 At Transit Nodes......................................12
      3.2.1 At NSH Transit Nodes................................12
      3.2.2 At an SF/Proxy......................................13
      3.2.3 At Other Forwarding Nodes...........................13
      3.3 At Exit/Egress........................................13
      3.4 Conservation of Packets...............................14

      4. Tunnel Congestion Feedback Support.....................15

      5. IANA Considerations....................................16
      5.1 SFC NSH Header ECN Bits...............................16
      5.2 IPFIX Information Element ID..........................16

      6. Security Considerations................................17

      7. Acknowledgements.......................................17

      Normative References......................................18
      Informative References....................................18

      Authors' Addresses........................................20

D. Eastlake, B. Briscoe, & A. Malis                             [Page 2]
INTERNET-DRAFT                             NSH ECN & Congestion Feedback

1. Introduction

   Explicit congestion notification (ECN [RFC3168]) allows a forwarding
   element to notify downstream devices of the onset of congestion
   without having to drop packets. Coupled with a means to feed
   information about congestion back to upstream nodes, this can improve
   network efficiency through better congestion control, frequently
   without packet drops. This document specifies ECN and congestion
   feedback support within a Service Function Chaining (SFC [RFC7665])
   architecture domain through use of the Network Service Header (NSH
   [RFC8300]) and IP Flow Information Export (IPFIX
   [TunnelCongFeedback]).

   It requires that all ingress and egress nodes of the SFC domain
   implement ECN. While congestion management will be the most effective
   if all interior nodes of the SFC domain implement ECN, some benefit
Show full document text