draft-ietf-avtcore-rtp-multi-stream-optimisation-03.txt | draft-ietf-avtcore-rtp-multi-stream-optimisation-04.txt | |||
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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: January 02, 2015 Ericsson | Expires: February 26, 2015 Ericsson | |||
Q. Wu | Q. Wu | |||
Huawei | Huawei | |||
C. Perkins | C. Perkins | |||
University of Glasgow | University of Glasgow | |||
July 01, 2014 | August 25, 2014 | |||
Sending Multiple Media Streams in a Single RTP Session: Grouping RTCP | Sending Multiple Media 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-03 | draft-ietf-avtcore-rtp-multi-stream-optimisation-04 | |||
Abstract | Abstract | |||
RTP allows multiple media streams to be sent in a single session, but | RTP allows multiple media 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 co-located and see the same reception quality. This | endpoint are co-located and see the same reception quality. This | |||
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 January 02, 2015. | This Internet-Draft will expire on February 26, 2015. | |||
Copyright Notice | Copyright Notice | |||
Copyright (c) 2014 IETF Trust and the persons identified as the | Copyright (c) 2014 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 9, line 22 ¶ | skipping to change at page 9, line 22 ¶ | |||
the RTCP XR packets. If multiple reporting sources are in use, the | the RTCP XR packets. If multiple reporting sources are in use, the | |||
reporting source that sends the SR/RR packets that relate to a | reporting source that sends the SR/RR packets that relate to a | |||
particular remote SSRC SHOULD send the RTCP XR reports about that | particular remote SSRC SHOULD send the RTCP XR reports about that | |||
SSRC. This is motivated as one commonly combine the RTCP XR metrics | SSRC. This is motivated as one commonly combine the RTCP XR metrics | |||
with the regular report block to more fully understand the situation. | with the regular report block to more fully understand the situation. | |||
Receiving these blocks in different compound packets reduces their | Receiving these blocks in different compound packets reduces their | |||
value as the measuring intervals are not synchronized in those cases. | value as the measuring intervals are not synchronized in those cases. | |||
Some RTCP XR report blocks are specific to particular types of media, | Some RTCP XR report blocks are specific to particular types of media, | |||
and might be relevant to only some members of a reporting group. For | and might be relevant to only some members of a reporting group. For | |||
example, it would make no sender for an SSRC that is receiving video | example, it would make no sense for an SSRC that is receiving video | |||
to send a VoIP metric RTCP XR report block. Such media specific RTCP | to send a VoIP metric RTCP XR report block. Such media specific RTCP | |||
XR report blocks MUST be sent by the SSRC to which they are relevant, | XR report blocks MUST be sent by the SSRC to which they are relevant, | |||
and MUST NOT be included in the common report sent by the reporting | and MUST NOT be included in the common report sent by the reporting | |||
source. This might mean that some SSRCs send RTCP XR packets in | source. This might mean that some SSRCs send RTCP XR packets in | |||
compound RTCP packets that contain an empty RTCP SR/RR packet, and | compound RTCP packets that contain an empty RTCP SR/RR packet, and | |||
that the time period covered by the RTCP XR packet is different to | that the time period covered by the RTCP XR packet is different to | |||
that covered by the RTCP SR/RR packet. If it is important that the | that covered by the RTCP SR/RR packet. If it is important that the | |||
RTCP XR packet and RTCP SR/RR packet cover the same time period, then | RTCP XR packet and RTCP SR/RR packet cover the same time period, then | |||
that source SHOULD be removed from the RTCP reporting group, and send | that source SHOULD be removed from the RTCP reporting group, and send | |||
standard RTCP packets instead. | standard RTCP packets instead. | |||
skipping to change at page 10, line 40 ¶ | skipping to change at page 10, line 40 ¶ | |||
(SDP) [RFC4566] attribute to indicate if the session participant is | (SDP) [RFC4566] attribute to indicate if the session participant is | |||
capable of supporting RTCP Reporting Groups for applications that use | capable of supporting RTCP Reporting Groups for applications that use | |||
SDP for configuration of RTP sessions. A participant that proposes | SDP for configuration of RTP sessions. A participant that proposes | |||
the use of RTCP Reporting Groups SHALL itself support the reception | the use of RTCP Reporting Groups SHALL itself support the reception | |||
of RTCP Reporting Groups. | of RTCP Reporting Groups. | |||
An offering client that wishes to use RTCP Reporting Groups MUST | An offering client that wishes to use RTCP Reporting Groups MUST | |||
include the attribute "a=rtcp-rgrp" in the SDP offer. If "a=rtcp- | include the attribute "a=rtcp-rgrp" in the SDP offer. If "a=rtcp- | |||
rgrp" is present in the offer SDP, the answerer that supports RTCP | rgrp" is present in the offer SDP, the answerer that supports RTCP | |||
Reporting Groups and wishes to use it SHALL include the "a=rtcp-rgrp" | Reporting Groups and wishes to use it SHALL include the "a=rtcp-rgrp" | |||
attribute in the answer. | attribute in the answer. The attribute takes no value. | |||
In declarative usage of SDP, such as the Real Time Streaming Protocol | In declarative usage of SDP, such as the Real Time Streaming Protocol | |||
(RTSP) [RFC2326] and the Session Announcement Protocol (SAP) | (RTSP) [RFC2326] and the Session Announcement Protocol (SAP) | |||
[RFC2974], the presence of the attribute indicates that the session | [RFC2974], the presence of the attribute indicates that the session | |||
participant MAY use RTCP Reporting Groups in its RTCP transmissions. | participant MAY use RTCP Reporting Groups in its RTCP transmissions. | |||
4. Properties of RTCP Reporting Groups | 4. Properties of RTCP Reporting Groups | |||
This section provides additional information on what the resulting | This section provides additional information on what the resulting | |||
properties are with the design specified in Section 3. The content | properties are with the design specified in Section 3. The content | |||
skipping to change at page 14, line 40 ¶ | skipping to change at page 14, line 40 ¶ | |||
SDP Attribute ("att-field"): | SDP Attribute ("att-field"): | |||
Attribute name: rtcp-rgrp | Attribute name: rtcp-rgrp | |||
Long form: RTCP Reporting Groups | Long form: RTCP Reporting Groups | |||
Type of name: att-field | Type of name: att-field | |||
Type of attribute: Media or session level | Type of attribute: Media or session level | |||
Subject to charset: No | Subject to charset: No | |||
Purpose: Negotiate or configure the use of the RTCP | Purpose: Negotiate or configure the use of the RTCP | |||
Reporting Group Extension. | Reporting Group Extension. | |||
Reference: [RFCXXXX] | Reference: [RFCXXXX] | |||
Values: See [RFCXXXX] | 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, W., and C. Perkins, | |||
"Sending Multiple Media Streams in a Single RTP Session", | "Sending Multiple Media Streams in a Single RTP Session", | |||
draft-ietf-avtcore-rtp-multi-stream-04 (work in progress), | draft-ietf-avtcore-rtp-multi-stream-05 (work in progress), | |||
May 2014. | July 2014. | |||
[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, March 1997. | Requirement Levels", BCP 14, RFC 2119, March 1997. | |||
[RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V. | [RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V. | |||
Jacobson, "RTP: A Transport Protocol for Real-Time | Jacobson, "RTP: A Transport Protocol for Real-Time | |||
Applications", STD 64, RFC 3550, July 2003. | Applications", STD 64, RFC 3550, July 2003. | |||
[RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session | [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session | |||
Description Protocol", RFC 4566, July 2006. | Description Protocol", RFC 4566, July 2006. | |||
End of changes. 8 change blocks. | ||||
9 lines changed or deleted | 9 lines changed or added | |||
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