Reliable Multicast Transport (rmt)

In addition to this official charter maintained by the IETF Secretariat, there is additional information about this working group on the Web at:

       Additional RMT Web Page

Last Modified: 2008-04-23

Additional information is available at tools.ietf.org/wg/rmt

Chair(s):

  • Lorenzo Vicisano <lorenzo@vicisano.net>

  • Brian Adamson <adamson@itd.nrl.navy.mil>

    Transport Area Director(s):

  • Magnus Westerlund <magnus.westerlund@ericsson.com>
  • Lars Eggert <lars.eggert@nokia.com>

    Transport Area Advisor:

  • Magnus Westerlund <magnus.westerlund@ericsson.com>

    Mailing Lists:

    General Discussion: rmt@ietf.org
    To Subscribe: rmt-request@ietf.org
    In Body: subscribe
    Archive: http://www.ietf.org/mail-archive/web/rmt/index.html

    Description of Working Group:

    The purpose of this WG is to standardize reliable multicast transport.


    Initial efforts have focused solely on the standardization of the
    one-to-many transport of large amounts of data. Due to the large
    number of applications that fall into this category, and the sometimes
    orthogonal requirements these applications exhibit, it is believed
    that a "one size fits all" protocol will be unable to meet the
    requirements of all applications. In recognition of this observation,
    this working group will standardize two protocol instantiations,
    initially as Experimental protocols, and then as warranted, in the
    standards track, from the following families:

    1) A NACK-based protocol.
    2) An "Asynchronous Layered Coding protocol that uses Forward Error
      Correction.

    The WG will carry out protocol standardization in general by composing
    a a set of RFCs that specify

    - building blocks: A set of easily-separable coarse-grained modular
    components that are common to multiple protocols along with abstract
    APIs that define a building block's access methods and their
    arguments.

    - protocol instantiations: Specifications that define the necessary
    gluing logic and minimal additional functionality required to realize
    a working protocol from one or more building blocks. These
    specifications will also include an abstract API that defines the
    interface between the protocol implementation and an application.

    The WG has previously completed work on three documents to assist in
    the standardization process. RFC2887 describes the design-space in
    which the one-to-many transport protocols will be developed. RFC3048
    explains the concepts of building-blocks and protocol
    instantiations. RFC3269 provides guidelines to authors of drafts that
    specify building-blocks and protocol instantiations.

    The WG will generate and submit for standardization drafts of the
    following building-blocks for use in the construction of the two
    protocols: congestion control, negative acknowledgments, forward error
    correction, and to address the RFC 2357 security requirements.

    Generic mechanisms for router assist are also considered for an
    additional building block. Initial work on the framework for
    router-assist has already been performed, the WG will evaluate whether
    to complete this task basing on available resource and interest.

    The WG will also standardize and generate RFCs for the following two
    protocol instantiations: A NACK-based protocol, and an Asynchronous
    Layered Coding (ALC) protocol that uses Forward Error Correction.
    RFC 3450 is the Experimental RFC of the ALC protocol instantiation.

    If new requirements are identified that cannot be satisfied with the
    building-blocks and protocol instantiations described above, the Area
    Directors in consultation with the IESG may add additional
    building-blocks and protocol instantiations to the working group
    deliverables.

    This working group will work closely with the Internet Research Task
    Force (IRTF) groups on Reliable Multicast (RMRG) and
    Secure Multicast (SMUG), especially for meeting the congestion control
    and security requirements mandated by RFC 2357. This working group may
    work with the Area Directors to recharter to standardize reliable
    multicast for additional scenarios beyond the one-to-many transport of
    bulk data once they are sufficiently well understood.

    Goals and Milestones:

    Done  Submit design-space, building-blocks, and guidelines drafts for publication as Informational RFCs
    Done  Initial Drafts for the following building blocks: negative acknowledgments, forward error correction, a generic signaling mechanism for router assist, and transport protection
    Done  Submit Initial Drafts for the two protocol instantiations.
    Done  Submit Initial Draft for Congestion Control
    Done  Complete building-block drafts WG Last-Call and submit for publication as Proposed Standard
    Done  Complete building blocks and protocol instantiations for ALC and submit for publication as Experimental RFC
    Done  WG Decision on whether to pursue the router-assist building block work. These milestones may have to be modified accordingly
    Done  Submit WEBRC (congestion control building block) for publication as Experimental
    Done  Submit NACK building block and protocol instantiation for publication as Experimental
    Done  Evaluate when and how the RMT Experimental specifications will be submitted for publication as Proposed Standard, and update this charter accordingly
    Sep 2005  Submit remaining congestion control building blocks (TFMCC, PGMCC) for publication as Experimental
    Dec 2005  Submit all the RMT Eperimental Specifications published before July 05 for publication as Proposed Standard
    Apr 2006  Submit all remaining RMT Eperimental Specifications for publication as Proposed Standard

    Internet-Drafts:

    Layered Coding Transport (LCT) Building Block (88540 bytes)
    Asynchronous Layered Coding (ALC) Protocol Instantiation (55333 bytes)
    Basic Forward Error Correction (FEC) Schemes (40817 bytes)
    Low Density Parity Check (LDPC) Staircase and Triangle Forward Error Correction (FEC) Schemes (69332 bytes)
    NACK-Oriented Reliable Multicast (NORM) Protocol (252717 bytes)
    Multicast Negative-Acknowledgment (NACK) Building Blocks (100452 bytes)
    Reed-Solomon Forward Error Correction (FEC) Schemes (61211 bytes)
    Security and Reliable Multicast Transport Protocols: Discussions and Guidelines (60084 bytes)

    Request For Comments:

    The Reliable Multicast Design Space for Bulk Data Transfer (RFC 2887) (51135 bytes)
    Reliable Multicast Transport Building Blocks for One-to-Many Bulk-Data Transfer (RFC 3048) (48965 bytes)
    Author Guidelines for RMT Building Blocks and Protocol Instantiation documents (RFC 3269) (25258 bytes)
    Asynchronous Layered Coding protocol instantiation (RFC 3450) (86022 bytes)
    Layered Coding Transport (LCT) Building Block (RFC 3451) (72594 bytes)
    Forward Error Correction Building Block (RFC 3452) (38368 bytes) obsoleted by RFC 5052
    The use of Forward Error Correction in Reliable Multicast (RFC 3453) (46853 bytes)
    Compact Forward Error Correction (FEC) Schemes (RFC 3695) (32012 bytes)
    Wave and Equation Based Rate Control building block (RFC 3738) (82584 bytes)
    FLUTE - File Delivery over Unidirectional Transport (RFC 3926) (81224 bytes)
    NACK-Oriented Reliable Multicast Protocol (NORM) (RFC 3940) (220549 bytes)
    NACK-Oriented Reliable Multicast (NORM) Building Blocks (RFC 3941) (92785 bytes)
    TCP-Friendly Multicast Congestion Control (TFMCC): Protocol Specification (RFC 4654) (72190 bytes)
    Forward Error Correction (FEC) Building Block (RFC 5052) (57754 bytes) obsoletes RFC 3452
    Raptor Forward Error Correction Scheme for Object Delivery (RFC 5053) (113743 bytes)
    IETF Secretariat - Please send questions, comments, and/or suggestions to ietf-web@ietf.org.

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