Bob Penfield wrote:
[snip]
> If the UAC only wants the first 200-OK, it can accept it. If it
> sees another 200-OK, it can just ACK it and send a BYE.
I have seen this answer many times.
But I have never seen any discussion of the kind of user
experience this provides.
>From a callee perspective this kind of behavior will be identical
to the failed predictive dialer calls I frequently get.
It seems like a bad idea to be devising a protocol that
makes this behavior even more common.
Minimally, it seems like there should be some way to
report the reason for the BYE.
It would be even better to report the problem sooner.
Why can't there be a NAC to send as an alternative to an ACK?
This could stop the call before it is fully started.
But either way, this would provide a hook to notify the
callee why the caller didn't follow through on the call.
When I answer a call, I would prefer to receive a message:
"Sorry, this call has already been answered by another party"
before being hung up. Of course the calling UA could do this,
but it is a bit much to expect that. With the reason signalled,
the called UA can present this in an appropriate way.
Paul Kyzivat
Cisco Systems
_______________________________________________
Sip-implementors mailing list
[EMAIL PROTECTED]
http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
