TCP Alternative Backoff with ECN (ABE)
draft-ietf-tcpm-alternativebackoff-ecn-01
Network Working Group N. Khademi
Internet-Draft M. Welzl
Intended status: Experimental University of Oslo
Expires: November 5, 2017 G. Armitage
Swinburne University of Technology
G. Fairhurst
University of Aberdeen
May 4, 2017
TCP Alternative Backoff with ECN (ABE)
draft-ietf-tcpm-alternativebackoff-ecn-01
Abstract
Recent Active Queue Management (AQM) mechanisms instantiate shallow
buffers with burst tolerance to minimise the time that packets spend
enqueued at a bottleneck. However, shallow buffering can cause
noticeable performance degradation when TCP is used over a network
path with a large bandwidth-delay-product. Traditional methods rely
on detecting network congestion through reported loss of transport
packets. Explicit Congestion Notification (ECN) instead allows a
router to directly signal incipient congestion. A sending endpoint
can distinguish when congestion is signalled via ECN, rather than by
packet loss. An ECN signal indicates that an AQM mechanism has done
its job, and therefore the bottleneck network queue is likely to be
shallow. This document therefore proposes an update to the TCP
sender-side ECN reaction in congestion avoidance to reduce the
FlightSize by a smaller amount than the congestion control
algorithm's reaction to loss. Future versions of this document will
also describe a corresponding method for the Stream Control
Transmission Protocol (SCTP).
Status of This Memo
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Khademi, et al. Expires November 5, 2017 [Page 1]
Internet-Draft ABE May 2017
This Internet-Draft will expire on November 5, 2017.
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Table of Contents
1. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Specification . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.1. Why Use ECN to Vary the Degree of Backoff? . . . . . . . 4
4.2. Focus on ECN as Defined in RFC3168 . . . . . . . . . . . 5
4.3. Discussion: Choice of ABE Multiplier . . . . . . . . . . 5
5. Status of the Update . . . . . . . . . . . . . . . . . . . . 6
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
8. Implementation Status . . . . . . . . . . . . . . . . . . . . 8
9. Security Considerations . . . . . . . . . . . . . . . . . . . 8
10. Revision Information . . . . . . . . . . . . . . . . . . . . 8
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
11.1. Normative References . . . . . . . . . . . . . . . . . . 9
11.2. Informative References . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11
1. Definitions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
2. Introduction
Explicit Congestion Notification (ECN) [RFC3168] makes it possible
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