draft-ietf-avt-post-repair-rtcp-xr-02.txt   draft-ietf-avt-post-repair-rtcp-xr-03.txt 
AVT A. Begen AVT A. Begen
Internet-Draft D. Hsu Internet-Draft D. Hsu
Intended status: Standards Track M. Lague Intended status: Standards Track M. Lague
Expires: April 20, 2009 Cisco Systems Expires: April 24, 2009 Cisco Systems
October 17, 2008 October 21, 2008
Post-Repair Loss RLE Report Block Type for RTCP XR Post-Repair Loss RLE Report Block Type for RTCP XR
draft-ietf-avt-post-repair-rtcp-xr-02 draft-ietf-avt-post-repair-rtcp-xr-03
Status of this Memo Status of this Memo
By submitting this Internet-Draft, each author represents that any By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79. aware will be disclosed, in accordance with Section 6 of BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
skipping to change at page 1, line 35 skipping to change at page 1, line 35
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt. http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html. http://www.ietf.org/shadow.html.
This Internet-Draft will expire on April 20, 2009. This Internet-Draft will expire on April 24, 2009.
Copyright Notice Copyright Notice
Copyright (C) The IETF Trust (2008). Copyright (C) The IETF Trust (2008).
Abstract Abstract
This document defines a new report block type within the framework of This document defines a new report block type within the framework of
RTP Control Protocol (RTCP) Extended Reports (XR). One of the RTP Control Protocol (RTCP) Extended Reports (XR). One of the
initial XR report block types is the Loss Run Length Encoding (RLE) initial XR report block types is the Loss Run Length Encoding (RLE)
skipping to change at page 2, line 17 skipping to change at page 2, line 17
repair is completed, one can determine the effectiveness of the loss- repair is completed, one can determine the effectiveness of the loss-
repair methods in an aggregated fashion. This document also defines repair methods in an aggregated fashion. This document also defines
the signaling of the Post-repair Loss RLE Report in the Session the signaling of the Post-repair Loss RLE Report in the Session
Description Protocol (SDP). Description Protocol (SDP).
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Requirements Notation . . . . . . . . . . . . . . . . . . . . . 4 2. Requirements Notation . . . . . . . . . . . . . . . . . . . . . 4
3. Post-Repair Loss RLE Report Block . . . . . . . . . . . . . . . 4 3. Post-Repair Loss RLE Report Block . . . . . . . . . . . . . . . 4
4. Session Description Protocol Signaling . . . . . . . . . . . . 5 4. Session Description Protocol Signaling . . . . . . . . . . . . 6
5. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 6
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 6 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 7
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7
8.1. Normative References . . . . . . . . . . . . . . . . . . . 7 8.1. Normative References . . . . . . . . . . . . . . . . . . . 7
8.2. Informative References . . . . . . . . . . . . . . . . . . 7 8.2. Informative References . . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8
Intellectual Property and Copyright Statements . . . . . . . . . . 9 Intellectual Property and Copyright Statements . . . . . . . . . . 9
1. Introduction 1. Introduction
RTP Control Protocol (RTCP) is the out-of-band control protocol for RTP Control Protocol (RTCP) is the out-of-band control protocol for
the applications that are using the Real-time Transport Protocol the applications that are using the Real-time Transport Protocol
(RTP) for media delivery and communications [RFC3550]. RTCP allows (RTP) for media delivery and communications [RFC3550]. RTCP allows
the RTP entities to monitor the data delivery and provides them the RTP entities to monitor the data delivery and provides them
minimal control functionality via sender and receiver reports as well minimal control functionality via sender and receiver reports as well
as other control packets. [RFC3611] expands the RTCP functionality as other control packets. [RFC3611] expands the RTCP functionality
skipping to change at page 3, line 30 skipping to change at page 3, line 30
report is usually collected only on the primary source stream before report is usually collected only on the primary source stream before
any loss-repair method is applied. Once one or more loss-repair any loss-repair method is applied. Once one or more loss-repair
methods, e.g., Forward Error Correction (FEC) [RFC5109] and/or methods, e.g., Forward Error Correction (FEC) [RFC5109] and/or
retransmission [RFC4588], are applied, some or all of the lost retransmission [RFC4588], are applied, some or all of the lost
packets on the primary source stream may be recovered. However, the packets on the primary source stream may be recovered. However, the
pre-repair Loss RLE cannot indicate which source packets were pre-repair Loss RLE cannot indicate which source packets were
recovered and which are still missing. Thus, the pre-repair Loss RLE recovered and which are still missing. Thus, the pre-repair Loss RLE
cannot specify how well the loss repair performed. cannot specify how well the loss repair performed.
This issue can be addressed by generating an additional report block This issue can be addressed by generating an additional report block
(within the same RTCP XR report), which reflects the packet receipt/ (within the same or a different RTCP XR report), which reflects the
loss events after all loss-repair methods are applied. This report packet receipt/loss events after all loss-repair methods are applied.
block, which we refer to as the Post-repair Loss RLE, indicates the This report block, which we refer to as the Post-repair Loss RLE,
remaining missing, i.e., unrepairable, source packets. When the pre- indicates the remaining missing, i.e., unrepairable, source packets.
repair and post-repair Loss RLEs are compared, the RTP sender or When the pre-repair and post-repair Loss RLEs are compared, the RTP
another third party entity can evaluate the effectiveness of the sender or another third party entity can evaluate the effectiveness
loss-repair methods (at the packet level) in an aggregated fashion. of the loss-repair methods in an aggregated fashion. To avoid any
To avoid any ambiguity in the evaluation, it is RECOMMENDED that the ambiguity in the evaluation, it is RECOMMENDED that the post-repair
post-repair Loss RLE is generated for the source packets that have no Loss RLE is generated for the source packets that have no further
further chance of being repaired. If the loss-repair method(s) may chance of being repaired. If the loss-repair method(s) may still
still recover one or more missing source packets, the post-repair recover one or more missing source packets, the post-repair Loss RLE
Loss RLE SHOULD NOT be sent until the loss-recovery process has been SHOULD NOT be sent until the loss-recovery process has been
completed. completed.
Similar to the pre-repair Loss RLE, the post-repair Loss RLE conveys
the receipt/loss events at the packet level and considers partially
repaired packets as unrepaired. Thus, methods that can do partially
recover the missing data SHOULD NOT be evaluated based on the
information provided by the Post-repair Loss RLE Reports.
Note that the idea of using pre-repair and post-repair Loss RLEs can Note that the idea of using pre-repair and post-repair Loss RLEs can
be further extended when multiple sequential loss-repair methods are be further extended when multiple sequential loss-repair methods are
applied to the primary source stream. Reporting the Loss RLEs before applied to the primary source stream. Reporting the Loss RLEs before
and after each loss-repair method can provide specific information and after each loss-repair method can provide specific information
about the individual performances of these methods. However, it can about the individual performances of these methods. However, it can
be a difficult task to quantify the specific contribution made by be a difficult task to quantify the specific contribution made by
each loss-repair method in hybrid systems, where different methods each loss-repair method in hybrid systems, where different methods
collectively work together to repair the lost source packets. Thus, collectively work together to repair the lost source packets. Thus,
in this specification we only consider reporting the Loss RLE after in this specification we only consider reporting the Loss RLE after
all loss-repair methods are applied. all loss-repair methods are applied.
 End of changes. 8 change blocks. 
19 lines changed or deleted 25 lines changed or added

This html diff was produced by rfcdiff 1.35. The latest version is available from http://tools.ietf.org/tools/rfcdiff/