Subject: [AVT] a question on compound RTCP

From: "leo 320" <[email-masked]>
Date: Thu, 24 Aug 2006 22:06:13 -0500

Hello,

By reading the following statements in RFC 3550, I'm wondering if the
compound RTCP is mandatory, i.e., all RTCP packets MUST be sent in the
compound RTCP format or not; in other words, if only SR or RR is available
and required, can it be sent in the individual RTCP format?

Any clarification will be very appreciated!

*Request for Comments: 3550 - RTP: A Transport Protocol for Real-Time
Applications*

3. Definitions
RTCP packet: ... Typically, multiple RTCP
      packets are sent together as a compound RTCP packet in a single
      packet of the underlying protocol; this is enabled by the length
      field in the fixed header of each RTCP packet.

6.1 RTCP Packet Format
Multiple RTCP packets *can be* concatenated without any intervening
   separators to form a compound RTCP packet that is sent in a single
   packet of the lower layer protocol, for example UDP.
......
Each individual RTCP packet in the compound packet may be processed
   independently with no requirements upon the order or combination of
   packets.  However, in order to perform the functions of the protocol,
   the following constraints are imposed:
......
Thus, all RTCP packets *MUST be* sent in a compound packet of at least
   two individual packets, with the following format:
......
_______________________________________________
Audio/Video Transport Working Group
[email-masked]
https://www1.ietf.org/mailman/listinfo/avt

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From: Colin Perkins <[email-masked]>
Date: Fri, 25 Aug 2006 08:50:09 +0100

On 25 Aug 2006, at 04:06, leo 320 wrote:
> By reading the following statements in RFC 3550, I'm wondering if  
> the compound RTCP is mandatory, i.e., all RTCP packets MUST be sent  
> in the compound RTCP format or not; in other words, if only SR or  
> RR is available and required, can it be sent in the individual RTCP  
> format?

No. All RTCP packets MUST be sent as compound packets.

Colin