Subject: [AVT] RTP: When to turn off RTCP reception reports

From: Stephen Casner <[email-masked]>
Date: Tue, 7 Jan 2003 16:04:30 -0800 (PST)

Numerous times we have had discussions on this mailing list regarding
whether sending RTCP is "required".  We've answered with the reasons
behind both SR for data senders and RR for receivers.

Igor Curcio cited the specific paragraph that appears both in Section
6.2 of the RTP spec and in Section 1 of draft-ietf-avt-rtcp-bw-05.txt
regarding the ability to turn off RTCP RRs by allocating zero
bandwidth for them, and asked that we clarify there that, in general,
RTCP reports should not be turned off.  I've added text in the RTP
spec to do this.  If you all agree that this is a good addition, I
will ask the RFC Editor to insert it into rtcp-bw as well.

                                                        -- Steve

OLD:

   Using
   two parameters allows RTCP reception reports to be turned off
   entirely for a particular session by setting the RTCP bandwidth for
   non-data-senders to zero while keeping the RTCP bandwidth for data
   senders non-zero so that sender reports can still be sent for inter-
   media synchronization. This may be appropriate for systems operating
   on unidirectional links or for sessions that don't require feedback
   on the quality of reception.

NEW:

   Using
   two parameters allows RTCP reception reports to be turned off
   entirely for a particular session by setting the RTCP bandwidth for
   non-data-senders to zero while keeping the RTCP bandwidth for data
   senders non-zero so that sender reports can still be sent for inter-
   media synchronization.  Turning off RTCP reception reports is NOT
   RECOMMENDED because they are needed for the functions listed at the
   beginning of Section 6, particularly reception quality feedback and
   congestion control.  However, doing so may be appropriate for systems
   operating on unidirectional links or for sessions that don't require
   feedback on the quality of reception or liveness of receivers and
   that have other means to avoid congestion.

_______________________________________________
Audio/Video Transport Working Group
[email-masked]
https://www1.ietf.org/mailman/listinfo/avt

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From: "David R. Oran" <[email-masked]>
Date: Tue, 07 Jan 2003 19:29:35 -0500

I believe the new wording is an improvement and support including it in the 
RFC.

Dave.

>    that have other means to avoid congestion.

------------------------
David R. Oran
Cisco Systems
7 Ladyslipper Lane
Acton, MA 01720
Office: +1 978 264 2048
VoIP: +1 408 571 4576
Email: [email-masked]

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From: Jonathan Rosenberg <[email-masked]>
Date: Tue, 07 Jan 2003 23:09:12 -0500

I concur.

-Jonathan R.

David R. Oran wrote:
> I believe the new wording is an improvement and support including it in 
> the RFC.
> 
> Dave.
> 

-- 
Jonathan D. Rosenberg, Ph.D.                72 Eagle Rock Ave.
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