Network Working Group T. Paila
Request for Comments: 3926 Nokia
Category: Experimental M. Luby
Digital Fountain
R. Lehtonen
TeliaSonera
V. Roca
INRIA Rhone-Alpes
R. Walsh
Nokia
October 2004
FLUTE - File Delivery over Unidirectional Transport
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).
Abstract
This document defines FLUTE, a protocol for the unidirectional
delivery of files over the Internet, which is particularly suited to
multicast networks. The specification builds on Asynchronous Layered
Coding, the base protocol designed for massively scalable multicast
distribution.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Applicability Statement . . . . . . . . . . . . . . . . 3
1.1.1. The Target Application Space . . . . . . . . . . 3
1.1.2. The Target Scale . . . . . . . . . . . . . . . . 4
1.1.3. Intended Environments . . . . . . . . . . . . . 4
1.1.4. Weaknesses . . . . . . . . . . . . . . . . . . . 4
2. Conventions used in this Document. . . . . . . . . . . . . . . 5
3. File delivery . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1. File delivery session . . . . . . . . . . . . . . . . . 6
3.2. File Delivery Table. . . . . . . . . . . . . . . . . . . 8
3.3. Dynamics of FDT Instances within file delivery session . 9
3.4. Structure of FDT Instance packets. . . . . . . . . . . . 11
Paila, et al. Experimental [Page 1]
RFC 3926 FLUTE October 2004
3.4.1. Format of FDT Instance Header . . . . . . . . . 12
3.4.2. Syntax of FDT Instance . . . . . . . . . . . . . 13
3.4.3. Content Encoding of FDT Instance . . . . . . . . 16
3.5. Multiplexing of files within a file delivery session . . 17
4. Channels, congestion control and timing . . . . . . . . . . . 18
5. Delivering FEC Object Transmission Information . . . . . . . . 19
5.1. Use of EXT_FTI for delivery of FEC Object Transmission
Information. . . . . . . . . . . . . . . . . . . . . . . 20
5.1.1. General EXT_FTI format . . . . . . . . . . . . . 20
5.1.2. FEC Encoding ID specific formats for EXT_FTI . . 21
5.2. Use of FDT for delivery of FEC Object Transmission
Information. . . . . . . . . . . . . . . . . . . . . . . 25
6. Describing file delivery sessions. . . . . . . . . . . . . . . 25
7. Security Considerations . . . . . . . . . . . . . . . . . . . 26
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 29
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 29
Normative References . . . . . . . . . . . . . . . . . . . . . 29
Informative References . . . . . . . . . . . . . . . . . . . . 30
A. Receiver operation (informative) . . . . . . . . . . . . . . . 32
B. Example of FDT Instance (informative). . . . . . . . . . . . . 33
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 34
Full Copyright Statement . . . . . . . . . . . . . . . . . . . 35
1. Introduction
This document defines FLUTE version 1, a protocol for unidirectional
delivery of files over the Internet. The specification builds on
Asynchronous Layered Coding (ALC), version 1 [2], the base protocol
designed for massively scalable multicast distribution. ALC defines
transport of arbitrary binary objects. For file delivery
applications mere transport of objects is not enough, however. The
end systems need to know what the objects actually represent. This
document specifies a technique called FLUTE - a mechanism for
signaling and mapping the properties of files to concepts of ALC in a
way that allows receivers to assign those parameters for received
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