multicast
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...
Reliable multicast transport is a desirable technology for the
efficient and reliable distribution of data to a group on the
...
... scalability requirements of different
potential reliable multicast applications and users [3]. This
document addresses ...
... negative-acknowledgment (NACK)-
oriented reliable multicast (NORM) protocols. While different
protocol instantiations may be required to meet specific application
...
... instantiations. This document describes the framework and common
"building block" components relevant to multicast protocols based
primarily on NACK operation for reliable transport ...
... NACK operation for reliable transport. While this
document discusses a large set of reliable multicast components and
issues relevant to NORM protocol design ...
... timers.
The potential relationships to other reliable multicast transport
building blocks (Forward Error Correction (FEC ...
...
This memo contains part of the definitions necessary to fully specify
a Reliable Multicast Transport protocol in accordance with RFC 2357.
As per RFC 2357 ...
... 2357.
As per RFC 2357, the use of any reliable multicast protocol in the
Internet requires an adequate congestion control scheme ...
...
While waiting for such a scheme to be available, or for an existing
scheme to be proven adequate, the Reliable Multicast Transport
working group (RMT ...
...
All of these areas are at least briefly discussed. Additionally,
other reliable multicast transport building block documents such as
[9] have been created ...
...
The implicit goal of a reliable multicast transport protocol is the
reliable delivery of data among a group ...
... delivery of data among a group of members communicating
using IP multicast datagram service. However, the specific service ...
... the application is attempting to provide can impact design decisions.
A most basic service model for reliable multicast transport is that
of "bulk transfer" which is a primary focus of this and other related
...
... senders and receivers participating in a reliable multicast transport
"session" may be able to join ...
... group sizes. It
may be desirable for some applications to scale along with the
multicast infrastructure's ability to scale. In its simplest form,
there are limits to the group size to which a NACK ...
... service across heterogeneous network topologies. It is desirable
that a reliable multicast protocol be capable of effectively
operating across a wide range of the networks ...
... inherently broadcast media with potentially large "fan-out" to which
IP multicast service is highly applicable. Additionally, policy
and/or technical issues may result in topologies ...
... service is highly applicable. Additionally, policy
and/or technical issues may result in topologies where multicast
connectivity is limited to a single source multicast ...
... multicast
connectivity is limited to a single source multicast (SSM) model from
a specific source [8 ...
... the performance and scalability of reliable multicast protocols,
there will continue to be a number of instances where this is not
available or practical. Any building block components for NACK ...
... available or practical. Any building block components for NACK-
oriented reliable multicast SHALL be capable of operating without
such assistance. However, it is RECOMMENDED that such protocols also
consider utilizing these features when available.
...
... forward error correction (FEC), etc.) may be applicable
to other forms of reliable multicast. In those cases, the discussion
below describes requirements ...
... requirements placed on those other general building
block areas from the standpoint of NACK-oriented reliable multicast.
Where applicable, other building block documents are referenced for
possible contribution to NORM ...
...
NORM senders will transmit data content to the multicast session.
The data content will be application dependent. The sender will
...
... GRTT
interval is a conservative estimate of the maximum span (with respect
to delay) of the multicast group across a network topology with
respect to given sender ...
... NORM instantiations SHOULD be able to
dynamically adapt to a wide range of multicast network topologies.
...
... GRTT and a group size estimate that is determined by other mechanisms
within the protocol or preset by the multicast application.
A simple algorithm ...
... Internet operation, a default value of K=4 is RECOMMENDED
for operation with multicast (to the group at large) NACK delivery ...
... experienced by a receiver. Such correlation MAY not be present in
multicast networks. This adjustment of backoff timeout selection may
require the creation of an "early NACK ...
...
The content of NACK messages generated by reliable multicast
receivers will include information detailing their current repair
...
... receiver set, it may be useful for the
sender to forward (via multicast) a representation of its aggregated
NACK content to the group ...
... group to allow for NACK suppression when there is
not multicast connectivity among the receiver set.
...
... FEC-based repair and the ordering of the repair response from the
sender that can improve reliable multicast efficiency:
1) When FEC ...
... performance,
in some types of bulk transfer applications (or for potential
interactive reliable multicast applications).
Group ...
... Reliable Multicast Member Identification ...
...
In a NORM protocol (or other multicast protocols) where there is the
potential for multiple sources of data, it is necessary to provide
some mechanism to uniquely identify the sources (and possibly some or
...
... result, some type of unique source identifier <sourceId> field should
be present in packets transmitted by reliable multicast session
members.
...
... type is static, discrete objects of finite size and the other is
continuous non-finite streams. A given application may wish to
reliably multicast data content using either one or both of these
paradigms. While it may be possible for some applications to further
generalize this model and provide mechanisms to encapsulate ...
... many applications to provide distinct support for static bulk objects
and messages with the context of a reliable multicast session. These
applications may include content caching servers, file transfer, or
...
... some applications may wish to encapsulate other bulk content (e.g.,
files) into one or more streams within a multicast session.
The components described within this building block document are
...
... The components described within this building block document are
envisioned to be applicable to both of these models with the
potential for a mix of both types within a single multicast session.
To support this requirement, the normal data content identification ...
... will be unique with respect to a given sender within the reliable
multicast session and during the time that sender is supporting a
specific transport ...
... NORM protocols that use these data content fields should also
be compatible with support for intermediate system assistance to
reliable multicast transport operation when available.
...
... performance enhancements to the
repair process of NACK-oriented and other reliable multicast
protocols [11], [12 ...
... detailed recommendations concerning application of FEC and standard
formats for related reliable multicast protocol messages.
...
... group or sender. Where it is
likely that exchange of reliable multicast data will occur among the
group on a "many-to-many" basis, there are alternative measurement
...
... hosts that may simplify RTT measurement. There are trade-offs in
multicast congestion control design that require further
consideration before a universal recommendation on RTT ...
... Congestion control that fairly shares available network capacity
with other reliable multicast and TCP instantiations is REQUIRED for
general Internet ...
... TCP instantiations is REQUIRED for
general Internet operation. The TCP-Friendly Multicast Congestion
Control (TFMCC) [16] or Pragmatic General Multicast ...
... TCP-Friendly Multicast Congestion
Control (TFMCC) [16] or Pragmatic General Multicast Congestion
Control (PGMCC) techniques [17] may be applied to NORM ...
... filter FEC repair messages to provide an intelligent "subcast" of
repair content to different legs of the multicast topology depending
on the repair needs learned from previous receiver ...
... data transfer. Properly
designed negative-acknowledgement (NACK)-oriented reliable multicast
(NORM ...
... delivery infrastructure above the basic
Layer 3 IP multicast service (e.g., unicast or hybrid
...
... services). Furthermore, the simplicity of a protocol
based on "flat" group-wide multicast distribution may offer
advantages for a broad range of distributed services ...
... receivers) multicast communication under the Any-
Source Multicast (ASM) model defined in RFC 1112std5 [2 ...
... of scalable operation in asymmetric topologies such as Single-Source
Multicast (SSM) [8] where there may only be unicast ...
... security vulnerabilities as other IP and IP multicast protocols.
NORM is compatible with IP security ...
... layer mechanisms are not
available. The IETF Multicast Security (msec) Working Group is also
developing solutions which may be applicable to NORM ...
... Mankin, A., Romanow, A., Bradner, S., and V. Paxson, "IETF Criteria for Evaluating Reliable Multicast Transport and Application Protocols", RFC 2357, June 1998. ...
... Kermode, R. and L. Vicisano, "Author Guidelines for Reliable Multicast Transport (RMT) Building Blocks and Protocol Instantiation documents", RFC 3269, April 2002. ...
... Nonnenmacher, J. and E. Biersack, "Optimal Multicast Feedback," in IEEE Infocom, San Francisco, California, p. 964, March/April 1998. ...
... Macker, J. and R. Adamson, "Quantitative Prediction of Nack Oriented Reliable Multicast (NORM) Feedback", Proc. IEEE MILCOM 2002, October 2002. ...
... Holbrook, H., "A Channel Model for Multicast", Ph.D. Dissertation, Stanford University, Department of Computer Science, Stanford, California, August 2001. ...
... Floyd, S., Jacobson, V., McCanne, S., Liu, C., and L. Zhang. "A Reliable Multicast Framework for Light-weight Sessions and Application Level Framing ...
... Macker, J., "Reliable Multicast Transport and Integrated Erasure-based Forward Error Correction", Proc. IEEE MILCOM 97, October 1997. ...
... Luby, M., Vicisano, L., Gemmell, J., Rizzo, L., Handley, M., and J. Crowcroft, "The Use of Forward Error Correction (FEC) in Reliable Multicast", RFC 3453, December 2002. ...
... Gossink, D. and J. Macker, "Reliable Multicast and Integrated Parity Retransmission with Channel Estimation", IEEE ...
... Widmer, J. and M. Handley, "Extending Equation-Based Congestion Control to Multicast Applications", Proc ACM SIGCOMM 2001, San Diego, August 2001. ...
... Rizzo, L., "pgmcc: A TCP-Friendly Single-Rate Multicast Congestion Control Scheme", Proc ACM SIGCOMM 2000, Stockholm, August 2000. ...
... Comparison of Sender-Initiated and Receiver-Initiated Reliable Multicast Protocols". In Proc. INFOCOM, San Francisco, CA, October 1993. ...
... B.N. Levine, J.J. Garcia-Luna-Aceves, "A Comparison of Known Classes of Reliable Multicast Protocols", Proc. International Conference on Network Protocols (ICNP-96), Columbus, Ohio, Oct 29--Nov 1, 1996. ...