DualQ Coupled AQMs for Low Latency, Low Loss and Scalable Throughput (L4S)
draft-ietf-tsvwg-aqm-dualq-coupled-04
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Active Internet-Draft (tsvwg WG)
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2018-03-05
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draft-briscoe-tsvwg-aqm-dualq-coupled
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IETF
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(None)
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plain text
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WG state
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WG Document
(wg milestone:
Sep 2018 - Submit "DualQ Couple...
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Document shepherd |
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Wesley Eddy
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IESG |
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I-D Exists
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Consensus Boilerplate |
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Unknown
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(None)
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Send notices to |
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Wesley Eddy <wes@mti-systems.com>
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Transport Area working group (tsvwg) K. De Schepper
Internet-Draft Nokia Bell Labs
Intended status: Experimental B. Briscoe, Ed.
Expires: September 6, 2018 CableLabs
O. Bondarenko
Simula Research Lab
I. Tsang
Nokia
March 5, 2018
DualQ Coupled AQMs for Low Latency, Low Loss and Scalable Throughput
(L4S)
draft-ietf-tsvwg-aqm-dualq-coupled-04
Abstract
Data Centre TCP (DCTCP) was designed to provide predictably low
queuing latency, near-zero loss, and throughput scalability using
explicit congestion notification (ECN) and an extremely simple
marking behaviour on switches. However, DCTCP does not co-exist with
existing TCP traffic---DCTCP is so aggressive that existing TCP
algorithms approach starvation. So, until now, DCTCP could only be
deployed where a clean-slate environment could be arranged, such as
in private data centres. This specification defines `DualQ Coupled
Active Queue Management (AQM)' to allow scalable congestion controls
like DCTCP to safely co-exist with classic Internet traffic. The
Coupled AQM ensures that a flow runs at about the same rate whether
it uses DCTCP or TCP Reno/Cubic, but without inspecting transport
layer flow identifiers. When tested in a residential broadband
setting, DCTCP achieved sub-millisecond average queuing delay and
zero congestion loss under a wide range of mixes of DCTCP and
`Classic' broadband Internet traffic, without compromising the
performance of the Classic traffic. The solution also reduces
network complexity and eliminates network configuration.
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 https://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
De Schepper, et al. Expires September 6, 2018 [Page 1]
Internet-Draft DualQ Coupled AQMs March 2018
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 September 6, 2018.
Copyright Notice
Copyright (c) 2018 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
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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 . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Problem and Scope . . . . . . . . . . . . . . . . . . . . 3
1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5
1.3. Features . . . . . . . . . . . . . . . . . . . . . . . . 6
2. DualQ Coupled AQM . . . . . . . . . . . . . . . . . . . . . . 7
2.1. Coupled AQM . . . . . . . . . . . . . . . . . . . . . . . 7
2.2. Dual Queue . . . . . . . . . . . . . . . . . . . . . . . 8
2.3. Traffic Classification . . . . . . . . . . . . . . . . . 8
2.4. Overall DualQ Coupled AQM Structure . . . . . . . . . . . 9
2.5. Normative Requirements for a DualQ Coupled AQM . . . . . 11
2.5.1. Functional Requirements . . . . . . . . . . . . . . . 11
2.5.2. Management Requirements . . . . . . . . . . . . . . . 12
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
4. Security Considerations . . . . . . . . . . . . . . . . . . . 13
4.1. Overload Handling . . . . . . . . . . . . . . . . . . . . 13
4.1.1. Avoiding Classic Starvation: Sacrifice L4S Throughput
or Delay? . . . . . . . . . . . . . . . . . . . . . . 14
4.1.2. Congestion Signal Saturation: Introduce L4S Drop or
Delay? . . . . . . . . . . . . . . . . . . . . . . . 15
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