Subject: [SIP] How many RTP streams?

From: "Fox, Mike" <[email-masked]>
Date: Thu, 13 Jul 2000 16:19:33 -0700

Just how many 2833 RTP streams should a UAC support? In terms of "best
practices" should each SIP Application Server (SAS) taking part in a session
receive it's own 2833 stream from the UAC, or should each application server
forward the stream to the next inline SAS? Forwarding would allow for some
feature interaction reduction by deleting recognized events and not
forwarding them to down stream devices, of course this adds delay. Perhaps
it would be helpful if a SAS could recognize the degree of delay sensitivity
in downstream devices. By limiting the number of 2833 and media RTP streams
a device emits, it may make for a more scaleable, less expensive to
implement, and less prone to denial of service attacks solution. 

On a similar topic, is it possible that one could mount a denial of service
attack against a specific host by leveraging the fact that a few bits of
call control to a lot of gateways could direct megabits bits of media
traffic towards a victim host?

Comments?

Mike Fox

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From: Jonathan Rosenberg <[email-masked]>
Date: Mon, 17 Jul 2000 01:15:47 -0400

"Fox, Mike" wrote:
> forward the stream to the next inline SAS? 

Since each app server will not know about any others, in all likelihood,
I don't see how any kind of cooperative process, like forwarding, could
work. In fact, an app server wouldn't even be able to determine if a UAS
is actually another app server or the final destination.

Forwarding would allow for some
> forwarding them to down stream devices, of course this adds delay.

This seems completely infeasible. How would one app server know what the
next one wants to do?

-Jonathan R.
-- 
Jonathan D. Rosenberg                       72 Eagle Rock Ave.
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