draft-ietf-avtcore-rtp-multi-stream-optimisation-10.txt | draft-ietf-avtcore-rtp-multi-stream-optimisation-11.txt | |||
---|---|---|---|---|
AVTCORE WG J. Lennox | AVTCORE WG J. Lennox | |||
Internet-Draft Vidyo | Internet-Draft Vidyo | |||
Intended status: Standards Track M. Westerlund | Intended status: Standards Track M. Westerlund | |||
Expires: June 13, 2016 Ericsson | Expires: June 17, 2016 Ericsson | |||
Q. Wu | Q. Wu | |||
Huawei | Huawei | |||
C. Perkins | C. Perkins | |||
University of Glasgow | University of Glasgow | |||
December 11, 2015 | December 15, 2015 | |||
Sending Multiple RTP Streams in a Single RTP Session: Grouping RTCP | Sending Multiple RTP Streams in a Single RTP Session: Grouping RTCP | |||
Reception Statistics and Other Feedback | Reception Statistics and Other Feedback | |||
draft-ietf-avtcore-rtp-multi-stream-optimisation-10 | draft-ietf-avtcore-rtp-multi-stream-optimisation-11 | |||
Abstract | Abstract | |||
RTP allows multiple RTP streams to be sent in a single session, but | RTP allows multiple RTP streams to be sent in a single session, but | |||
requires each Synchronisation Source (SSRC) to send RTCP reception | requires each Synchronisation Source (SSRC) to send RTCP reception | |||
quality reports for every other SSRC visible in the session. This | quality reports for every other SSRC visible in the session. This | |||
causes the number of RTCP reception reports to grow with the number | causes the number of RTCP reception reports to grow with the number | |||
of SSRCs, rather than the number of endpoints. In many cases most of | of SSRCs, rather than the number of endpoints. In many cases most of | |||
these RTCP reception reports are unnecessary, since all SSRCs of an | these RTCP reception reports are unnecessary, since all SSRCs of an | |||
endpoint are normally co-located and see the same reception quality. | endpoint are normally co-located and see the same reception quality. | |||
skipping to change at page 1, line 44 ¶ | skipping to change at page 1, line 44 ¶ | |||
Internet-Drafts are working documents of the Internet Engineering | Internet-Drafts are working documents of the Internet Engineering | |||
Task Force (IETF). Note that other groups may also distribute | Task Force (IETF). Note that other groups may also distribute | |||
working documents as Internet-Drafts. The list of current Internet- | working documents as Internet-Drafts. The list of current Internet- | |||
Drafts is at http://datatracker.ietf.org/drafts/current/. | Drafts is at http://datatracker.ietf.org/drafts/current/. | |||
Internet-Drafts are draft documents valid for a maximum of six months | Internet-Drafts are draft documents valid for a maximum of six months | |||
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." | |||
This Internet-Draft will expire on June 13, 2016. | This Internet-Draft will expire on June 17, 2016. | |||
Copyright Notice | Copyright Notice | |||
Copyright (c) 2015 IETF Trust and the persons identified as the | Copyright (c) 2015 IETF Trust and the persons identified as the | |||
document authors. All rights reserved. | document authors. All rights reserved. | |||
This document is subject to BCP 78 and the IETF Trust's Legal | This document is subject to BCP 78 and the IETF Trust's Legal | |||
Provisions Relating to IETF Documents | Provisions Relating to IETF Documents | |||
(http://trustee.ietf.org/license-info) in effect on the date of | (http://trustee.ietf.org/license-info) in effect on the date of | |||
publication of this document. Please review these documents | publication of this document. Please review these documents | |||
skipping to change at page 4, line 18 ¶ | skipping to change at page 4, line 18 ¶ | |||
A group of co-located SSRCs that see identical network conditions can | A group of co-located SSRCs that see identical network conditions can | |||
form an RTCP reporting group. If reporting groups are in use, an RTP | form an RTCP reporting group. If reporting groups are in use, an RTP | |||
endpoint with multiple SSRCs MAY put those SSRCs into a reporting | endpoint with multiple SSRCs MAY put those SSRCs into a reporting | |||
group if their view of the network is identical; i.e., if they report | group if their view of the network is identical; i.e., if they report | |||
on traffic received at the same interface of an RTP endpoint. SSRCs | on traffic received at the same interface of an RTP endpoint. SSRCs | |||
with different views of the network MUST NOT be put into the same | with different views of the network MUST NOT be put into the same | |||
reporting group. | reporting group. | |||
An endpoint that has combined its SSRCs into an RTCP reporting group | An endpoint that has combined its SSRCs into an RTCP reporting group | |||
will choose one (or a subset) of those SSRCs as a "reporting source" | will choose one (or a subset) of those SSRCs to act as "reporting | |||
for that RTCP reporting group. A reporting source will send RTCP SR/ | source(s)" for that RTCP reporting group. A reporting source will | |||
RR reception quality reports on behalf of the other members of the | send RTCP SR/RR reception quality reports on behalf of the other | |||
RTCP reporting group. A reporting source MUST suppress the RTCP SR/ | members of the RTCP reporting group. A reporting source MUST | |||
RR reports that relate to other members of the reporting group, and | suppress the RTCP SR/RR reports that relate to other members of the | |||
only report on remote SSRCs. The other members (non reporting | reporting group, and only report on remote SSRCs. The other members | |||
sources) of the RTCP reporting group will suppress their RTCP | (non reporting sources) of the RTCP reporting group will suppress | |||
reception quality reports, and instead send an RTCP RGRS packet (see | their RTCP reception quality reports, and instead send an RTCP RGRS | |||
Section 3.2.2) to indicate that they are part of an RTCP reporting | packet (see Section 3.2.2) to indicate that they are part of an RTCP | |||
group and give the SSRCs of the reporting sources. | reporting group and give the SSRCs of the reporting sources. | |||
If there are large numbers of remote SSRCs in the RTP session, then | If there are large numbers of remote SSRCs in the RTP session, then | |||
the reception quality reports generated by the reporting source might | the reception quality reports generated by the reporting source might | |||
grow too large to fit into a single compound RTCP packet, forcing the | grow too large to fit into a single compound RTCP packet, forcing the | |||
reporting source to use a round-robin policy to determine what remote | reporting source to use a round-robin policy to determine what remote | |||
SSRCs it includes in each compound RTCP packet, and so reducing the | SSRCs it includes in each compound RTCP packet, and so reducing the | |||
frequency of reports on each SSRC. To avoid this, in sessions with | frequency of reports on each SSRC. To avoid this, in sessions with | |||
large numbers of remote SSRCs, an RTCP reporting group MAY use more | large numbers of remote SSRCs, an RTCP reporting group MAY use more | |||
than one reporting source. If several SSRCs are acting as reporting | than one reporting source. If several SSRCs are acting as reporting | |||
sources for an RTCP reporting group, then each reporting source MUST | sources for an RTCP reporting group, then each reporting source MUST | |||
skipping to change at page 6, line 45 ¶ | skipping to change at page 6, line 45 ¶ | |||
SSRC of the packet sender, and a list of reporting sources for the | SSRC of the packet sender, and a list of reporting sources for the | |||
RTCP reporting group of which the packet sender is a member. | RTCP reporting group of which the packet sender is a member. | |||
0 1 2 3 | 0 1 2 3 | |||
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 | 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 | |||
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
|V=2|P| SC | PT=RGRS(TBA) | length | | |V=2|P| SC | PT=RGRS(TBA) | length | | |||
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| SSRC of packet sender | | | SSRC of packet sender | | |||
+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ | +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ | |||
: List of SSRCs for the Reporting Source(s) : | : List of SSRC(s) for the Reporting Source(s) : | |||
: ... : | : ... : | |||
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
The fields in the RTCP RGRS packet have the following definition: | The fields in the RTCP RGRS packet have the following definition: | |||
version (V): 2 bits unsigned integer. This field identifies the RTP | version (V): 2 bits unsigned integer. This field identifies the RTP | |||
version. The current RTP version is 2. | version. The current RTP version is 2. | |||
padding (P): 1 bit. If set, the padding bit indicates that the RTCP | padding (P): 1 bit. If set, the padding bit indicates that the RTCP | |||
packet contains additional padding octets at the end that are not | packet contains additional padding octets at the end that are not | |||
skipping to change at page 15, line 24 ¶ | skipping to change at page 15, line 24 ¶ | |||
Values: None | Values: None | |||
The definition of the "a=rtcp-rgrp" SDES attribute is given in | The definition of the "a=rtcp-rgrp" SDES attribute is given in | |||
Section 3.6 of this memo. | Section 3.6 of this memo. | |||
7. References | 7. References | |||
7.1. Normative References | 7.1. Normative References | |||
[I-D.ietf-avtcore-rtp-multi-stream] | [I-D.ietf-avtcore-rtp-multi-stream] | |||
Lennox, J., Westerlund, M., Wu, W., and C. Perkins, | Lennox, J., Westerlund, M., Wu, Q., and C. Perkins, | |||
"Sending Multiple Media Streams in a Single RTP Session", | "Sending Multiple RTP Streams in a Single RTP Session", | |||
draft-ietf-avtcore-rtp-multi-stream-10 (work in progress), | draft-ietf-avtcore-rtp-multi-stream-11 (work in progress), | |||
November 2015. | December 2015. | |||
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate | [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate | |||
Requirement Levels", BCP 14, RFC 2119, | Requirement Levels", BCP 14, RFC 2119, | |||
DOI 10.17487/RFC2119, March 1997, | DOI 10.17487/RFC2119, March 1997, | |||
<http://www.rfc-editor.org/info/rfc2119>. | <http://www.rfc-editor.org/info/rfc2119>. | |||
[RFC3264] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model | [RFC3264] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model | |||
with Session Description Protocol (SDP)", RFC 3264, | with Session Description Protocol (SDP)", RFC 3264, | |||
DOI 10.17487/RFC3264, June 2002, | DOI 10.17487/RFC3264, June 2002, | |||
<http://www.rfc-editor.org/info/rfc3264>. | <http://www.rfc-editor.org/info/rfc3264>. | |||
End of changes. 7 change blocks. | ||||
19 lines changed or deleted | 19 lines changed or added | |||
This html diff was produced by rfcdiff 1.46. The latest version is available from http://tools.ietf.org/tools/rfcdiff/ |