Wave and Equation Based Rate Control (WEBRC) Building Block
RFC 3738
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Type |
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RFC - Experimental
(April 2004; No errata)
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Last updated |
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2013-03-02
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IETF
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plain text
pdf
html
bibtex
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WG state
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(None)
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Document shepherd |
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No shepherd assigned
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| IESG |
IESG state |
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RFC 3738 (Experimental)
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Consensus Boilerplate |
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Unknown
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Telechat date |
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Responsible AD |
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Allison Mankin
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Send notices to |
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<Roger.Kermode@motorola.com>, <lorenzo@cisco.com>
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Network Working Group M. Luby
Request for Comments: 3738 Digital Fountain
Category: Experimental V. Goyal
M.I.T.
April 2004
Wave and Equation Based Rate Control (WEBRC) Building Block
Status of this Memo
This memo defines an Experimental Protocol for the Internet
community. It does not specify an Internet standard of any kind.
Discussion and suggestions for improvement are requested.
Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2004). All Rights Reserved.
Abstract
This document specifies Wave and Equation Based Rate Control (WEBRC),
which provides rate and congestion control for data delivery. WEBRC
is specifically designed to support protocols using IP multicast. It
provides multiple-rate, congestion-controlled delivery to receivers,
i.e., different receivers joined to the same session may be receiving
packets at different rates depending on the bandwidths of their
individual connections to the sender and on competing traffic along
these connections. WEBRC requires no feedback from receivers to the
sender, i.e., it is a completely receiver-driven congestion control
protocol. Thus, it is designed to scale to potentially massive
numbers of receivers attached to a session from a single sender.
Furthermore, because each individual receiver adjusts to the
available bandwidth between the sender and that receiver, there is
the potential to deliver data to each individual receiver at the
fastest possible rate for that receiver, even in a highly
heterogeneous network architecture, using a single sender.
Luby & Goyal Experimental [Page 1]
RFC 3738 WEBRC Building Block April 2004
Table of Contents
1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Rationale . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Functionality . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1. Sender Operation . . . . . . . . . . . . . . . . . . . . 9
3.1.1. Sender inputs and initialization. . . . . . . . . 9
3.1.2. Sending packets to the session. . . . . . . . . . 10
3.2. Receiver Operation . . . . . . . . . . . . . . . . . . . 12
3.2.1. Receiver inputs and initialization. . . . . . . . 12
3.2.2. Receiver measurements and calculations. . . . . . 13
3.2.2.1. Average loss probability . . . . . . . . 13
3.2.2.2. Average round-trip time. . . . . . . . . 16
3.2.2.3. Rate Equation. . . . . . . . . . . . . . 16
3.2.2.4. Epochs . . . . . . . . . . . . . . . . . 17
3.2.2.5. Average reception rate . . . . . . . . . 17
3.2.2.6. Slow start . . . . . . . . . . . . . . . 19
3.2.2.7. Target rate. . . . . . . . . . . . . . . 20
3.2.3. Receiver events . . . . . . . . . . . . . . . . . 20
3.2.3.1. Packet reception . . . . . . . . . . . . 20
3.2.3.2. First packet after join. . . . . . . . . 20
3.2.3.3. Time slot change . . . . . . . . . . . . 20
3.2.3.4. Loss event . . . . . . . . . . . . . . . 21
3.2.3.5. Epoch change . . . . . . . . . . . . . . 21
3.2.3.6. Join the next higher layer . . . . . . . 21
3.2.3.7. Join timeout . . . . . . . . . . . . . . 23
3.2.3.8. Exceptional timeouts . . . . . . . . . . 23
4. Applicability Statement . . . . . . . . . . . . . . . . . . . 23
4.1. Environmental Requirements and Considerations. . . . . . 23
5. Packet Header Fields. . . . . . . . . . . . . . . . . . . . . 25
5.1. Short Format Congestion Control Information. . . . . . . 26
5.2. Long Format Congestion Control Information . . . . . . . 27
6. Requirements From Other Building Blocks . . . . . . . . . . . 28
7. Security Considerations . . . . . . . . . . . . . . . . . . . 28
8. References. . . . . . . . . . . . . . . . . . . . . . . . . . 29
8.1. Normative References . . . . . . . . . . . . . . . . . . 29
8.2. Informative References . . . . . . . . . . . . . . . . . 30
9. Authors' Addresses. . . . . . . . . . . . . . . . . . . . . . 31
10. Full Copyright Statement. . . . . . . . . . . . . . . . . . . 32
Luby & Goyal Experimental [Page 2]
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