The Benefits of using Explicit Congestion Notification (ECN)
draft-ietf-aqm-ecn-benefits-05
| The information below is for an old version of the document |
| Document |
Type |
|
Active Internet-Draft (aqm WG)
|
|
Last updated |
|
2015-06-20
|
|
Replaces |
|
draft-welzl-ecn-benefits
|
|
Stream |
|
IETF
|
|
Intended RFC status |
|
(None)
|
|
Formats |
|
plain text
pdf
html
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)
|
Network Working Group G. Fairhurst
Internet-Draft University of Aberdeen
Intended status: Informational M. Welzl
Expires: December 25, 2015 University of Oslo
June 23, 2015
The Benefits of using Explicit Congestion Notification (ECN)
draft-ietf-aqm-ecn-benefits-05
Abstract
The goal of this document is to describe the potential benefits when
applications use a transport that enables Explicit Congestion
Notification (ECN). The document outlines the principal gains in
terms of increased throughput, reduced delay and other benefits when
ECN is used over a network path that includes equipment that supports
ECN-marking. It also discusses challenges for successful deployment
of ECN. It does not propose new algorithms to use ECN, nor does it
describe the details of implementation of ECN in endpoint devices
(Internet hosts), routers or other network devices.
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 http://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 December 25, 2015.
Copyright Notice
Copyright (c) 2015 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
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
Fairhurst & Welzl Expires December 25, 2015 [Page 1]
Internet-Draft Benefits of ECN June 2015
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
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
2. Benefit of using ECN to avoid Congestion Loss . . . . . . . . 4
2.1. Improved Throughput . . . . . . . . . . . . . . . . . . . 4
2.2. Reduced Head-of-Line Blocking . . . . . . . . . . . . . . 5
2.3. Reduced Probability of RTO Expiry . . . . . . . . . . . . 5
2.4. Applications that do not Retransmit Lost Packets . . . . 6
2.5. Making Incipient Congestion Visible . . . . . . . . . . . 7
2.6. Opportunities for new Transport Mechanisms . . . . . . . 7
3. Network Support for ECN . . . . . . . . . . . . . . . . . . . 8
3.1. The ECN Field . . . . . . . . . . . . . . . . . . . . . . 9
3.2. Forwarding ECN-Capable IP Packets . . . . . . . . . . . . 9
3.3. Enabling ECN in Network Devices . . . . . . . . . . . . . 9
3.4. Co-existance of ECN and non-ECN flows . . . . . . . . . . 10
3.5. Bleaching and Middlebox Requirements to deploy ECN . . . 10
3.6. Tunneling ECN and the use of ECN by Lower Layer Networks 11
4. Using ECN across the Internet . . . . . . . . . . . . . . . . 11
4.1. Partial Deployment . . . . . . . . . . . . . . . . . . . 11
4.2. Detecting whether a Path Really Supports ECN . . . . . . 12
4.3. Detecting ECN Receiver Feedback Cheating . . . . . . . . 12
5. Summary: Enabling ECN in Network Devices and Hosts . . . . . 12
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 14
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
8. Security Considerations . . . . . . . . . . . . . . . . . . . 14
9. Revision Information . . . . . . . . . . . . . . . . . . . . 15
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
10.1. Normative References . . . . . . . . . . . . . . . . . . 16
10.2. Informative References . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18
1. Introduction
Internet Transports (such as TCP and SCTP) are implemented in
endpoints (Internet hosts) and are designed to detect and react to
network congestion. Congestion may be detected by loss of an IP
Show full document text