Guidelines for Adding Congestion Notification to Protocols that Encapsulate IP
draft-ietf-tsvwg-ecn-encap-guidelines-14
Transport Area Working Group B. Briscoe
Internet-Draft Independent
Updates: 3819 (if approved) J. Kaippallimalil
Intended status: Best Current Practice Futurewei
Expires: May 19, 2021 November 15, 2020
Guidelines for Adding Congestion Notification to Protocols that
Encapsulate IP
draft-ietf-tsvwg-ecn-encap-guidelines-14
Abstract
The purpose of this document is to guide the design of congestion
notification in any lower layer or tunnelling protocol that
encapsulates IP. The aim is for explicit congestion signals to
propagate consistently from lower layer protocols into IP. Then the
IP internetwork layer can act as a portability layer to carry
congestion notification from non-IP-aware congested nodes up to the
transport layer (L4). Following these guidelines should assure
interworking among IP layer and lower layer congestion notification
mechanisms, whether specified by the IETF or other standards bodies.
This document updates the advice to subnetwork designers about ECN in
RFC 3819.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on May 19, 2021.
Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved.
Briscoe & Kaippallimalil Expires May 19, 2021 [Page 1]
Internet-Draft ECN Encapsulation Guidelines November 2020
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Update to RFC 3819 . . . . . . . . . . . . . . . . . . . 5
1.2. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 7
3. Modes of Operation . . . . . . . . . . . . . . . . . . . . . 9
3.1. Feed-Forward-and-Up Mode . . . . . . . . . . . . . . . . 9
3.2. Feed-Up-and-Forward Mode . . . . . . . . . . . . . . . . 11
3.3. Feed-Backward Mode . . . . . . . . . . . . . . . . . . . 12
3.4. Null Mode . . . . . . . . . . . . . . . . . . . . . . . . 14
4. Feed-Forward-and-Up Mode: Guidelines for Adding Congestion
Notification . . . . . . . . . . . . . . . . . . . . . . . . 14
4.1. IP-in-IP Tunnels with Shim Headers . . . . . . . . . . . 15
4.2. Wire Protocol Design: Indication of ECN Support . . . . . 16
4.3. Encapsulation Guidelines . . . . . . . . . . . . . . . . 18
4.4. Decapsulation Guidelines . . . . . . . . . . . . . . . . 20
4.5. Sequences of Similar Tunnels or Subnets . . . . . . . . . 22
4.6. Reframing and Congestion Markings . . . . . . . . . . . . 22
5. Feed-Up-and-Forward Mode: Guidelines for Adding Congestion
Notification . . . . . . . . . . . . . . . . . . . . . . . . 23
6. Feed-Backward Mode: Guidelines for Adding Congestion
Notification . . . . . . . . . . . . . . . . . . . . . . . . 24
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25
8. Security Considerations . . . . . . . . . . . . . . . . . . . 25
9. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . 26
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 26
11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 27
12. Comments Solicited . . . . . . . . . . . . . . . . . . . . . 27
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 27
13.1. Normative References . . . . . . . . . . . . . . . . . . 27
13.2. Informative References . . . . . . . . . . . . . . . . . 28
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