Subject: minimum RTCP interval

From: Sylvie Brunelle <[email-masked]>
Date: Thu, 22 Jun 2000 14:35:46 +0100

Hi everybody,

I have a question concerning the minimum RTCP interval. A value of 5sec
is RECOMMENDED but how was this value chosen (why not 3,4, 6, 7...)? Is
this choice based on some study?
Cheers,
Sylvie Brunelle

---

From: Jonathan Rosenberg <[email-masked]>
Date: Fri, 23 Jun 2000 02:45:32 -0400

I was not privy to the initial discussions in the selection; I think it
was a reasonable compromise between freshness of data and bandwidth
usage.

Recent work we have done with timer reconsideration has shown that this
number, for receivers, really needs to be several times larger, at
least, than typical network latencies. Otherwise, step joins can result
in large RTCP floods (multicast only, of course).

The latest version of RTP does allow this 5s value to be scaled down if
RTCP bandwidth usage is increased. See section 6.2 of:
http://www.ietf.org/internet-drafts/draft-ietf-avt-rtp-new-07.txt

-Jonathan R.

-- 
Jonathan D. Rosenberg                       72 Eagle Rock Ave.
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