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Re: [AVT] FW: New Version Notification for draft-begen-avt-rtp-cnames-01

"Ali C. Begen (abegen)" <abegen@cisco.com> Tue, 25 May 2010 02:09 UTC

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Date: Mon, 24 May 2010 19:09:19 -0700
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From: "Ali C. Begen (abegen)" <abegen@cisco.com>
To: Peter Musgrave <peter.musgrave@magorcorp.com>
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Subject: Re: [AVT] FW: New Version Notification for draft-begen-avt-rtp-cnames-01
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Hi Peter,

Indeed. Could you have a look at today's revision? It discusses when per-session or persistent cnames should be used.

http://tools.ietf.org/html/draft-begen-avt-rtp-cnames-02

-acbegen

> -----Original Message-----
> From: Peter Musgrave [mailto:peter.musgrave@magorcorp.com]
> Sent: Monday, May 24, 2010 10:03 PM
> To: Ali C. Begen (abegen)
> Cc: avt@ietf.org
> Subject: Re: [AVT] FW: New Version Notification for draft-begen-avt-rtp-cnames-01
> 
> Hi Ali,
> 
> In the context of synchronizing multiple media flows (multiple audio
> streams or audio+video) from a unique source - cnames can be useful to
> determine which media streams are from a common node and need to be
> aligned in time for playback. The use of a session specific cname
> would break this usage (or we would require e.g the audio and video
> subsystems to agree on a session specific cname - which is an
> implementation constraint I would prefer to avoid).
> 
> Is it worth mentioning that session specific cnames are not suitable
> in cases such as this?
> 
> Peter Musgrave
> 
> 
> 
> On Wed, May 5, 2010 at 10:34 AM, Ali C. Begen (abegen) <abegen@cisco.com> wrote:
> > Here is the new version of the CNAME draft.
> >
> > http://www.ietf.org/id/draft-begen-avt-rtp-cnames-01.txt
> >
> > We took the comments into consideration. Hopefully, the text is almost complete now. Feedback is
> welcome.
> >
> > -acbegen
> >
> > -----Original Message-----
> > From: IETF I-D Submission Tool [mailto:idsubmission@ietf.org]
> > Sent: Wednesday, May 05, 2010 10:31 AM
> > To: Ali C. Begen (abegen)
> > Cc: csp@csperkins.org
> > Subject: New Version Notification for draft-begen-avt-rtp-cnames-01
> >
> >
> > A new version of I-D, draft-begen-avt-rtp-cnames-01.txt has been successfully submitted by Ali Begen
> and posted to the IETF repository.
> >
> > Filename:        draft-begen-avt-rtp-cnames
> > Revision:        01
> > Title:           Guidelines for Choosing RTP Control Protocol (RTCP) Canonical Names (CNAMEs)
> > Creation_date:   2010-05-05
> > WG ID:           Independent Submission
> > Number_of_pages: 6
> >
> > Abstract:
> > The RTP Control Protocol (RTCP) Canonical Name (CNAME) is a
> > persistent transport-level identifier for an RTP endpoint.  While the
> > Synchronization Source (SSRC) identifier of an RTP endpoint may
> > change if a collision is detected, or when the RTP application is
> > restarted, the CNAME is meant to stay unchanged, so that RTP
> > endpoints can be uniquely identified and associated with their RTP
> > media streams.  For proper functionality, CNAMEs should be unique
> > within the participants of an RTP session.  However, the
> > recommendations for choice of the RTCP CNAME provided in RFC 3550 are
> > insufficient to achieve this uniqueness.  This memo updates the
> > guidelines in RFC 3550 to allow endpoints to choose unique CNAMEs.
> >
> >
> >
> > The IETF Secretariat.
> >
> >
> > _______________________________________________
> > Audio/Video Transport Working Group
> > avt@ietf.org
> > https://www.ietf.org/mailman/listinfo/avt
> >

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