Coding and congestion control in transport
draft-irtf-nwcrg-coding-and-congestion-01
NWCRG N. Kuhn
Internet-Draft CNES
Intended status: Informational E. Lochin
Expires: August 9, 2020 ISAE-SUPAERO
F. Michel
UCLouvain
M. Welzl
University of Oslo
February 6, 2020
Coding and congestion control in transport
draft-irtf-nwcrg-coding-and-congestion-01
Abstract
Coding is a reliability mechanism that is distinct and separated from
the loss detection of congestion controls. Using coding can be a
useful way to better deal with tail losses or with networks with non-
congestion losses. However, coding mechanisms should not hide
congestion signals. This memo offers a discussion of how coding and
congestion control can coexist. This document can help the
comparison of FEC schemes by identifying at which level they are
operating with respect to the transport congestion control.
This document is the product of the Coding for Efficient Network
Communications Research Group (NWCRG). The scope of the document is
end-to-end communications: coding for tunnels is out-of-the scope of
the document.
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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material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 9, 2020.
Kuhn, et al. Expires August 9, 2020 [Page 1]
Internet-Draft Coding and congestion February 2020
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Separate channels, separate entities . . . . . . . . . . . . 3
3. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. Type of application . . . . . . . . . . . . . . . . . . . 4
3.2. End-to-end . . . . . . . . . . . . . . . . . . . . . . . 4
3.3. Objective of the document . . . . . . . . . . . . . . . . 5
4. FEC above the transport . . . . . . . . . . . . . . . . . . . 5
5. FEC within the transport . . . . . . . . . . . . . . . . . . 6
6. FEC below the transport . . . . . . . . . . . . . . . . . . . 6
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
9. Security Considerations . . . . . . . . . . . . . . . . . . . 8
10. Informative References . . . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction
There are cases where deploying coding improves the quality of the
transmission. As an example, it may take time for the server to
detect tail losses and this would impact the experience of
applications using short flows. Another example are networks where
non-congestion losses are persistent and prevent a sender from
exploiting the link capacity.
Coding is a reliability mechanism that is distinct and separated from
the loss detection of congestion controls. [RFC5681] defines TCP as
a loss-based congestion control; because coding repairs such losses,
blindly applying it may easily lead to an implementation that also
hides a congestion signal to the sender. It is important to ensure
that such information hiding does not occur.
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