[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [AVT] Fwd: I-D Action:draft-perkins-avt-rapid-rtp-sync-03.txt
Hi Thomas,
> > - Could the draft also mention about the other useful properties of
> > having a sender report earlier? I also think a more appropriate name
> > could be found for this message.
> >
>
> As I said before, naming is not the problem. Which useful properties
> should be added here?
I am not sure but one could be regarding the extended RTP seqnums. An SR would enable the receiver to learn the ext seqnum.
> > - Section 4.2 says "The frequency of intersing ntp header
> exs is up to
> > the sender." Any guidance/constraints on this?
> >
>
> Guidelines would be helpful, but we didn't want to constraint this
> approach. I think it is clear the more often you insert them, the
> earlier you can, e.g., start the decoding order recovery. I
> think this
> is definitely depending on the application. What would you
> expect here?
> Do you think about guidance with respect to overhead against
> the time it
> takes to be synced?
That could be one aspect. Others may include whether the receiver has to process all such header extensions, the processing overhead of such extensions, issues with MTU limits... Not sure if all these will make sense, though.
BR,
-acbegen
> > - There are a few inconsistent intra-document references.
> >
>
> Thanks, will check that.
>
> > Chairs:
> > I support this draft to become a WG item as it has two good
> solution for
> > (timestamp) synchronization for RTP flows.
> >
> > -acbegen
> >
> >
>
> Best regards,
> Thomas
>
>
> --
> Thomas Schierl
> --------------
> Fraunhofer HHI
>
>
>
> >> -----Original Message-----
> >> From: avt-bounces at ietf.org [mailto:avt-bounces at ietf.org] On
> >> Behalf Of Colin Perkins
> >> Sent: Monday, March 09, 2009 12:43 PM
> >> To: avt at ietf.org WG
> >> Subject: [AVT] Fwd: I-D
> Action:draft-perkins-avt-rapid-rtp-sync-03.txt
> >>
> >> The changes in this version are primarily editorial; we're
> >> aware that
> >> not all the open issues have been addressed yet. Any further
> >> comments
> >> are welcomed.
> >>
> >> Chairs: we'd like this to be considered as an AVT working group
> >> draft, as indicated privately.
> >>
> >> Cheers,
> >> Colin
> >>
> >>
> >>
> >>
> >> Begin forwarded message:
> >>
> >>> From: Internet-Drafts at ietf.org
> >>> Date: 9 March 2009 17:15:02 GMT
> >>> To: i-d-announce at ietf.org
> >>> Subject: I-D Action:draft-perkins-avt-rapid-rtp-sync-03.txt
> >>> Reply-To: internet-drafts at ietf.org
> >>>
> >>> A New Internet-Draft is available from the on-line
> Internet-Drafts
> >>> directories.
> >>>
> >>> Title : Rapid Synchronisation of RTP Flows
> >>> Author(s) : C. Perkins, T. Schierl
> >>> Filename : draft-perkins-avt-rapid-rtp-sync-03.txt
> >>> Pages : 17
> >>> Date : 2009-03-09
> >>>
> >>> This memo outlines how RTP multimedia sessions are
> synchronised, and
> >>> discusses how rapidly such synchronisation can occur. We
> show that
> >>> most RTP sessions can be synchronised immediately, but
> that the use
> >>> of video switching multipoint conference units (MCUs) or
> >>>
> >> large source
> >>
> >>> specific multicast (SSM) groups can greatly increase the initial
> >>> synchronisation delay. This increase in delay can be
> >>>
> >> unacceptable to
> >>
> >>> some applications that use layered and/or
> multi-description codecs.
> >>>
> >>> This memo updates the RTP Control Protocol (RTCP) timing rules to
> >>> reduce the initial synchronisation delay for SSM sessions. A new
> >>> feedback packet is defined for use with the Extended RTP
> Profile for
> >>> RTCP-based Feedback (RTP/AVPF), allowing video switching MCUs to
> >>> rapidly request resynchronisation. Two new RTP header
> >>>
> >> extensions are
> >>
> >>> defined to allow rapid synchronisation of late joiners, and
> >>>
> >> guarantee
> >>
> >>> correct timestamp based decoding order recovery for layered
> >>>
> >> codecs in
> >>
> >>> the presence of clock skew.
> >>>
> >>> A URL for this Internet-Draft is:
> >>> http://www.ietf.org/internet-drafts/draft-perkins-avt-rapid-rtp-
> >>> sync-03.txt
> >>>
> >>> Internet-Drafts are also available by anonymous FTP at:
> >>> ftp://ftp.ietf.org/internet-drafts/
> >>>
> >>> Below is the data which will enable a MIME compliant mail reader
> >>> implementation to automatically retrieve the ASCII version of the
> >>> Internet-Draft.
> >>> Content-Type: text/plain
> >>> Content-ID: <2009-03-09100610.I-D at ietf.org>
> >>>
> >>> _______________________________________________
> >>> I-D-Announce mailing list
> >>> I-D-Announce at ietf.org
> >>> https://www.ietf.org/mailman/listinfo/i-d-announce
> >>> Internet-Draft directories: http://www.ietf.org/shadow.html
> >>> or ftp://ftp.ietf.org/ietf/1shadow-sites.txt
> >>>
> >> _______________________________________________
> >> Audio/Video Transport Working Group
> >> avt at ietf.org
> >> https://www.ietf.org/mailman/listinfo/avt
> >>
> >>
> > _______________________________________________
> > Audio/Video Transport Working Group
> > avt at ietf.org
> > https://www.ietf.org/mailman/listinfo/avt
> >
> >
> >
>
>
>
> ----
> Visit us at
>
> OFC 2009 / March 24-26 / San Diego, California / Hall B1, Booth 411
> http://www.ofcnfoec.org/
>
> Web 2.0 Expo / March 31 - April 03 / San Francisco,
> California / Booth 415
> http://www.web2expo.com/webexsf2009
>