Data Center Fast Congestion Management
draft-even-iccrg-dc-fast-congestion-00
|
Document |
Type |
|
Active Internet-Draft (individual)
|
|
Last updated |
|
2019-10-23
|
|
Stream |
|
(None)
|
|
Intended RFC status |
|
(None)
|
|
Formats |
|
plain text
pdf
htmlized
bibtex
|
Stream |
Stream state |
|
(No stream defined) |
|
Consensus Boilerplate |
|
Unknown
|
|
RFC Editor Note |
|
(None)
|
IESG |
IESG state |
|
I-D Exists
|
|
Telechat date |
|
|
|
Responsible AD |
|
(None)
|
|
Send notices to |
|
(None)
|
TSVWG R. Even
Internet-Draft Huawei
Intended status: Informational R. Huang
Expires: April 25, 2020 Huawei Technologies Co., Ltd.
October 23, 2019
Data Center Fast Congestion Management
draft-even-iccrg-dc-fast-congestion-00
Abstract
Fast congestion control is discussed in academic papers as well as in
the different standard bodies. There is no one proposal for
providing a solution that will work for all use cases leading to
multiple approaches. By congestion control we refer to an end to end
solution and not only to the congestion control algorithm on the
sender side. This document describes the current state of flow
control and congestion for Data Centers and proposes future
directions.
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
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 April 25, 2020.
Copyright Notice
Copyright (c) 2019 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
Even & Huang Expires April 25, 2020 [Page 1]
Internet-Draft DC Fast Congestion October 2019
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
2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Alternative Congestion Management mechanisms . . . . . . . . 4
4.1. Mechanisms based on estimation of network status . . . . 4
4.2. Network provides limited information . . . . . . . . . . 4
4.2.1. ECN and DCTCP . . . . . . . . . . . . . . . . . . . . 5
4.2.2. DCQCN . . . . . . . . . . . . . . . . . . . . . . . . 5
4.2.3. SCE - Some Congestion Experienced . . . . . . . . . . 6
4.2.4. L4S - Low Latency, Low Loss, Scalable Throughput . . 7
4.3. Network provides more information . . . . . . . . . . . . 8
4.4. Network provides proactive control . . . . . . . . . . . 9
5. Summary and Proposal . . . . . . . . . . . . . . . . . . . . 9
5.1. Reflect the network status more accurately . . . . . . . 10
5.2. Notify the reaction point as soon as possible. . . . . . 10
6. Security Considerations . . . . . . . . . . . . . . . . . . . 11
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
8.1. Normative References . . . . . . . . . . . . . . . . . . 11
8.2. Informative References . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15
1. Introduction
Fast congestion control is discussed in academic papers as well as in
the different standard bodies. There is no one proposal for
providing a solution that will work for all use cases leading to
multiple approaches. By congestion control we refer to an end to end
solution and not only to the congestion control algorithm on the
sender side.
The major use case that we are looking at is congestion control for
Data Centers, a controlled environment[RFC8085]. With the emerging
Distributed Storage, AI/HPC (High Performance Computing), Machine
Learning, etc., modern datacenter applications demand high
throughput(40Gbps and above) with ultra-low latency of less than 10
microsecond per hop from the network, with low CPU overhead. For the
end to end the latency should be less than 50usec, this value is
based on DCQCN [DCQCN] The high link speed (>40Gb/s) in Data Centers
Show full document text