Re: draft-ietf-mmusic-sip-session-timer-00.txt

[Jonathan Rosenberg <[e-mail]>]

Dean Willis wrote:
> 
> Jonathan wrote:
> > Dean Willis wrote:
> > >
> > > How about renewing at 1/2 T, where T is the minimum time unit on the
> > > proxy chain. If T is greater than 1 minute or so, this
> . . .
> >
> > I'm not sure we need to specify anything for this. Sending at
> > 1/2T, then
> > 3/2T, 5/2 T, etc., only delays the problem by T. What I mean
> > is lets say
> > each proxy starts its timer when the response comes down the proxy
> > chain, at t=0. Now, the client resends at 1/2 T, which is
> > fast enough to
> > refresh things. Now, each proxy expects to see the next before 3/2 T.
> > THe client sends at 3/2 T, but because of timing
> > inconsistencies, packet
> > loss, clock skew, and latencies, it comes too late for some servers.
> 
> Not quite what I meant.
> 
> If we have duration T, then refresh interval is 1/2 T -- so client
> refreshes at 1/2 T, 2/2 T, 3/2 T, 4/2 T, and so on -- always starting
> 1/2 T before expiration of the current timers.

Sorry for my misunderstanding. I believe this is pretty much what I was
suggesting. Whether the client sends at a lower rate than the
Session-Timer value, and servers timeout using the Session-Timer value,
or clients send at Session-Timer, and serves timeout with an interval
larger, is 6 on one hand, 1/2 a dozen on the other. It just needs to be
consistent.

-Jonathan R.

-- 
Jonathan D. Rosenberg                       Lucent Technologies
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