Layered Coding Transport (LCT) Building Block
RFC 5651

Network Working Group                                            M. Luby
Request for Comments: 5651                                     M. Watson
Obsoletes: 3451                                              L. Vicisano
Category: Standards Track                                 Qualcomm, Inc.
                                                            October 2009

             Layered Coding Transport (LCT) Building Block

Abstract

   The Layered Coding Transport (LCT) Building Block provides transport
   level support for reliable content delivery and stream delivery
   protocols.  LCT is specifically designed to support protocols using
   IP multicast, but it also provides support to protocols that use
   unicast.  LCT is compatible with congestion control that provides
   multiple rate delivery to receivers and is also compatible with
   coding techniques that provide reliable delivery of content.  This
   document obsoletes RFC 3451.

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.

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Luby, et al.                Standards Track                     [Page 1]
RFC 5651                   LCT Building Block               October 2009

   Without obtaining an adequate license from the person(s) controlling
   the copyright in such materials, this document may not be modified
   outside the IETF Standards Process, and derivative works of it may
   not be created outside the IETF Standards Process, except to format
   it for publication as an RFC or to translate it into languages other
   than English.

Table of Contents

   1. Introduction ....................................................3
   2. Rationale .......................................................3
   3. Functionality ...................................................4
   4. Applicability ...................................................7
      4.1. Environmental Requirements and Considerations ..............9
      4.2. Delivery Service Models ...................................10
      4.3. Congestion Control ........................................13
   5. Packet Header Fields ...........................................13
      5.1. LCT Header Format .........................................13
      5.2. Header-Extension Fields ...................................18
           5.2.1. General ............................................18
           5.2.2. EXT_TIME Header Extension ..........................20
   6. Operations .....................................................23
      6.1. Sender Operation ..........................................23
      6.2. Receiver Operation ........................................25
   7. Requirements from Other Building Blocks ........................26
   8. Security Considerations ........................................28
      8.1. Session and Object Multiplexing and Termination ...........28
      8.2. Time Synchronization ......................................29
      8.3. Data Transport ............................................29
   9. IANA Considerations ............................................29
      9.1. Namespace Declaration for LCT Header Extension Types ......29
      9.2. LCT Header Extension Type Registration ....................30
   10. Acknowledgments ...............................................30
   11. Changes from RFC 3451 .........................................31
   12. References ....................................................31
      12.1. Normative References .....................................31