> -----Original Message-----
> From: Eric Burger [mailto:[EMAIL PROTECTED]
>
> Let us take two scenarios for the easy case of transporting user stimulus.
> In the first case, the user presses a button and hangs up.  Because of
> normal Internet routing, the INFO (Invite-based Notification Function
> Output
> ;-) message arrives after the BYE arrives.  What to do?  What if the
> button
> pressed was "don't launch missiles?"

And what happens if the Bye gets to the far end before a 2833 event?  
Improbable but not impossible.  I would expect an application providing a 
"don't launch missiles" type user input to provide a "missile launch order 
confirmed" that the user would wait to hear before hanging up.  ;)


> In the second case, the application is using digit maps, because the
> application developer realizes that 1100 bytes of SIP headers to transport
> one byte of user stimulus information is stupid.  The device buffers some
> digits, but the user hangs up.  What does the endpoint do?  Does it send
> the
> collected digits?  Does it eat the collected digits?  Any argument other
> than an explicit negotiation (like KPML does) is not going to work in the
> general case.  This is because if we say, for DTMF, "always send buffered
> digits," then what we are really saying is, "always send what you have
> before the dialog terminates."  I could easily envision packages that
> would
> have tons of state that is immediately irrelevant at dialog termination.
> Dumping tons of bytes on the network again totally defeats the "We want
> this
> because it is lightweight" argument.

I'm not sure whether whomever writes a info-dtmf event package someday would 
define it to support digit maps or not... my guess is they would not.  But even 
if they did, I would assume the digits would be discarded in such a case, and 
defined to do so.  So what?  The user hung up, without pressing a sequence of 
digits that matched a map.  What's wrong with discarding the digits?

-hadriel


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