Forward Error Correction (FEC) Building Block
RFC 5052

Network Working Group                                          M. Watson
Request for Comments: 5052                                       M. Luby
Obsoletes: 3452                                              L. Vicisano
Category: Standards Track                               Digital Fountain
                                                             August 2007

             Forward Error Correction (FEC) Building Block

Status of This Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The IETF Trust (2007).

Abstract

   This document describes how to use Forward Error Correction (FEC)
   codes to efficiently provide and/or augment reliability for bulk data
   transfer over IP multicast.  This document defines a framework for
   the definition of the information that needs to be communicated in
   order to use an FEC code for bulk data transfer, in addition to the
   encoded data itself, and for definition of formats and codes for
   communication of that information.  Both information communicated
   with the encoded data itself and information that needs to be
   communicated 'out-of-band' are considered.  The procedures for
   specifying new FEC codes, defining the information communication
   requirements associated with those codes and registering them with
   the Internet Assigned Numbers Authority (IANA) are also described.
   The requirements on Content Delivery Protocols that wish to use FEC
   codes defined within this framework are also defined.  The companion
   document titled "The Use of Forward Error Correction (FEC) in
   Reliable Multicast" describes some applications of FEC codes for
   delivering content.  This document obsoletes RFC 3452.

Watson, et al.              Standards Track                     [Page 1]
RFC 5052                   FEC Building Block                August 2007

Table of Contents

   1. Introduction ....................................................3
   2. Definitions and Abbreviations ...................................4
   3. Requirements Notation ...........................................4
   4. Rationale .......................................................5
   5. Applicability Statement .........................................6
   6. Functionality ...................................................6
      6.1. FEC Schemes ................................................8
      6.2. FEC Object Transmission Information .......................10
           6.2.1. Transport of FEC Object Transmission Information ...11
           6.2.2. Opacity of FEC Object Transmission Information .....12
           6.2.3. Mandatory FEC Object Transmission
                  Information Elements ...............................12
           6.2.4. Common FEC Object Transmission Information
                  Elements ...........................................12
           6.2.5. Scheme-Specific FEC Object Transmission
                  Information Element ................................13
      6.3. FEC Payload ID ............................................13
   7. FEC Scheme Specifications ......................................14
   8. CDP Specifications .............................................17
   9. Common Algorithms ..............................................18
      9.1. Block Partitioning Algorithm ..............................18
           9.1.1. First Step .........................................18
           9.1.2. Second step ........................................19
   10. Requirements from Other Building Blocks .......................20
   11. Security Considerations .......................................20
   12. IANA Considerations ...........................................21
      12.1. Explicit IANA Assignment Guidelines ......................21
   13. Changes from RFC 3452 .........................................22
   14. Acknowledgments ...............................................23
   15. References ....................................................23
      15.1. Normative References .....................................23
      15.2. Informative References ...................................23

Watson, et al.              Standards Track                     [Page 2]
RFC 5052                   FEC Building Block                August 2007

1.  Introduction

   This document describes how to use Forward Error Correction (FEC)
   codes to provide support for reliable delivery of content within the