Re: [AVTCORE] FW: I-D Action: draft-ietf-avtcore-idms-07.txt

[Kevin Gross <[e-mail]>]

Ray has asked me to add to his comments and assure AVTCORE members that in
preparing this revision the authors also considered the following issues
discussed at IETF 84:

Which packet to report on - We decided to allow flexibility in which RTP
packet is used to report network delay. Flexibility allows implementations
to optimize reporting to get the most useful information to the MSAS
quickly. We do not believe interoperability or performance is compromised
by this flexibility.

draft-wu-xrblock-rtcp-xr-one-way-delay - We considered whether this
proposal could be used instead of the application-specific reporting
mechanism proposed in our draft. We found this unsuitable for the following
reasons.

   1. The IDMS proposal directly reports one-way delay of the RTP packets
   of the stream under control by IDMS. The one-way-delay proposal measures
   one-way delay using RTCP packets. RTP delay is what we care about for
   proper IDMS operation. RTCP packets are likely to experience different
   (shorter) delay due to their different (smaller) size.
   2. The one-way-delay proposal does not include a Media Stream
   Correlation Identifier. The MSAS requires this information to do its job.
   If it is not included in the XR, it will need to be signaled through
   another means significantly altering and complicating the system.
   3. The one-way-delay proposal does not include a presentation timestamp
   making the precise synchronization required by some IDMS applications
   difficult or impossible.


Kevin Gross
[phone]
Media Network Consultant
AVA Networks - www.AVAnw.com <http://www.avanw.com/>, www.X192.org



On Thu, Oct 11, 2012 at 1:24 AM, Brandenburg, R. (Ray) van <
[e-mail]> wrote:

> Hi all,
>
> I've just uploaded a new version of the IDMS draft. This new version
> includes the comments received during the WGLC which were not yet included
> in the -06 version and a solution to the packet reporting issue that we
> discussed in Vancouver.
>
> I believe that with this version all WGLC comments have been addressed.
>
> Best regards,
>
> Ray van Brandenburg
>
>
>
> -----Original Message-----
> From: [e-mail] [mailto:[e-mail]] On Behalf Of
> [e-mail]
> Sent: donderdag 11 oktober 2012 9:19
> To: [e-mail]
> Cc: [e-mail]
> Subject: [AVTCORE] I-D Action: draft-ietf-avtcore-idms-07.txt
>
>
> A New Internet-Draft is available from the on-line Internet-Drafts
> directories.
>  This draft is a work item of the Audio/Video Transport Core Maintenance
> Working Group of the IETF.
>
>         Title           : Inter-destination Media Synchronization using
> the RTP Control Protocol (RTCP)
>         Author(s)       : Ray van Brandenburg
>                           Hans Stokking
>                           Oskar van Deventer
>                           Fernando Boronat
>                           Mario Montagud
>                           Kevin Gross
>         Filename        : draft-ietf-avtcore-idms-07.txt
>         Pages           : 24
>         Date            : 2012-10-11
>
> Abstract:
>    This document gives information on an RTP Control Protocol (RTCP)
>    Packet Type and RTCP Extended Report (XR) Block Type including
>    associated Session Description Protocol (SDP) parameters for Inter-
>    Destination Media Synchronization (IDMS).  This document mandates the
>    use of the RTCP XR Block Type 12, which is used to collect media
>    playout information from participants in a group playing out
>    (watching, listening, etc.) a specific RTP media stream.  This RTCP
>    XR Block Type is specified and registered with IANA by ETSI.  The
>    RTCP packet type specified by this document is used to distribute a
>    common target playout point to which all the distributed receivers,
>    sharing a media experience, can synchronize.
>
>    Typical use cases in which IDMS is usefull are social TV, shared
>    service control (i.e. applications where two or more geographically
>    separated users are watching a media stream together), distance
>    learning, networked video walls, networked loudspeakers, etc.
>
>
> The IETF datatracker status page for this draft is:
> https://datatracker.ietf.org/doc/draft-ietf-avtcore-idms
>
> There's also a htmlized version available at:
> http://tools.ietf.org/html/draft-ietf-avtcore-idms-07
>
> A diff from the previous version is available at:
> http://www.ietf.org/rfcdiff?url2=draft-ietf-avtcore-idms-07
>
>
> Internet-Drafts are also available by anonymous FTP at:
> ftp://ftp.ietf.org/internet-drafts/
>
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