draft-ietf-avt-rapid-rtp-sync-08.txt | draft-ietf-avt-rapid-rtp-sync-09.txt | |||
---|---|---|---|---|
Network Working Group C. Perkins | Network Working Group C. Perkins | |||
Internet-Draft University of Glasgow | Internet-Draft University of Glasgow | |||
Updates: RFC3550 T. Schierl | Updates: RFC3550 T. Schierl | |||
(if approved) Fraunhofer HHI | (if approved) Fraunhofer HHI | |||
Intended status: Standards Track December 22, 2009 | Intended status: Standards Track January 8, 2010 | |||
Expires: June 25, 2010 | Expires: July 12, 2010 | |||
Rapid Synchronisation of RTP Flows | Rapid Synchronisation of RTP Flows | |||
draft-ietf-avt-rapid-rtp-sync-08.txt | draft-ietf-avt-rapid-rtp-sync-09.txt | |||
Status of this Memo | Status of this Memo | |||
This Internet-Draft is submitted to IETF in full conformance with the | This Internet-Draft is submitted to IETF in full conformance with the | |||
provisions of BCP 78 and BCP 79. | provisions of BCP 78 and 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 | |||
other groups may also distribute working documents as Internet- | other groups may also distribute working documents as Internet- | |||
Drafts. | Drafts. | |||
skipping to change at page 1, line 34 ¶ | skipping to change at page 1, line 34 ¶ | |||
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 June 25, 2010. | This Internet-Draft will expire on July 12, 2010. | |||
Copyright Notice | Copyright Notice | |||
Copyright (c) 2009 IETF Trust and the persons identified as the | Copyright (c) 2010 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 in effect on the date of | Provisions Relating to IETF Documents in effect on the date of | |||
publication of this document (http://trustee.ietf.org/license-info). | publication of this document (http://trustee.ietf.org/license-info). | |||
Please review these documents carefully, as they describe your rights | Please review these documents carefully, as they describe your rights | |||
and restrictions with respect to this document. | and restrictions with respect to this document. | |||
Abstract | Abstract | |||
skipping to change at page 14, line 19 ¶ | skipping to change at page 14, line 19 ¶ | |||
Note: The inclusion of an RTP header extension will reduce the | Note: The inclusion of an RTP header extension will reduce the | |||
efficiency of RTP header compression, if it is used. Furthermore, | efficiency of RTP header compression, if it is used. Furthermore, | |||
middle boxes which do not understand the header extensions may remove | middle boxes which do not understand the header extensions may remove | |||
them or may not update the content according to this memo. | them or may not update the content according to this memo. | |||
In all cases, irrespective of whether in-band NTP timestamp format | In all cases, irrespective of whether in-band NTP timestamp format | |||
timestamps are included or not, regular RTCP SR packets MUST be sent | timestamps are included or not, regular RTCP SR packets MUST be sent | |||
to provide backwards compatibility with receivers that synchronise | to provide backwards compatibility with receivers that synchronise | |||
RTP flows according to [1], and robustness in the face of middleboxes | RTP flows according to [1], and robustness in the face of middleboxes | |||
(RTP translators) that might strip RTP header extensions. The sender | (RTP translators) that might strip RTP header extensions. If the | |||
reports are also required to receive the upper 8 bit of the Seconds | Variant B/56-bit NTP RTP header extension is used, RTCP sender | |||
of the NTP timestamp format timestamp not included in the Variant | reports MUST be used to derive the upper 8 bit of the Seconds for the | |||
B/56-bit NTP RTP header extension (although this may generally be | NTP timestamp format timestamp. | |||
inferred from context). | ||||
When the SDP is used, the use of the RTP header extensions defined | When the SDP is used, the use of the RTP header extensions defined | |||
above MUST be indicated as specified in [6]. Therefore the following | above MUST be indicated as specified in [6]. Therefore the following | |||
URIs MUST be used: | URIs MUST be used: | |||
o The URI used for signalling the use of Variant A/64-bit NTP RTP | o The URI used for signalling the use of Variant A/64-bit NTP RTP | |||
header extension in SDP is "urn:ietf:params:rtp-hdrext:ntp-64". | header extension in SDP is "urn:ietf:params:rtp-hdrext:ntp-64". | |||
o The URI used for signalling the use of Variant B/56-bit NTP RTP | o The URI used for signalling the use of Variant B/56-bit NTP RTP | |||
header extension in SDP is "urn:ietf:params:rtp-hdrext:ntp-56". | header extension in SDP is "urn:ietf:params:rtp-hdrext:ntp-56". | |||
End of changes. 5 change blocks. | ||||
10 lines changed or deleted | 9 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/ |