Subject: RTP question

From: Magnus Westerlund <[email-masked]>
Date: Tue, 18 Apr 2000 11:17:20 +0200

Hello!

I have two questions regarding RTP.

The first one concerns the initialization of the variable avg_rtcp_size.
draft-ietf-avt-rtp-new-07 section 6.3.2 says:

   Upon joining the session, the participant initializes tp to 0, tc to
   0, senders to 0, pmembers to 1, members to 1, we_sent to false,
   rtcp_bw to the specified fraction of the session bandwidth, initial
   to true, and
            -->      avg_rtcp_size to the size of the very first packet
   constructed by the application. <--

   Is it not more reasonable to initialize avg_rtcp_size to a size that
it is probable that the first
RTCP packet will have? I think the current text is to unspecified and
hard to interpret.

The second question is about section 6.3.5 Timing Out an SSRC.

Is there a reason why the time out interval is set to M*Td and not to
the M latest RTCP transmission interval?
You could save the need of a last active timer for each member and
instead use a much smaller status variable counting how many periods
since last active. Is there no problem with premature timing out of
users when you have many users leaving a session, especially if they do
not send BYE message?

Magnus Westerlund

Audio Technology, Ericsson Research
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