At 09:03 AM 12/31/2004, Erik Versaevel wrote:
My problem is that we don't control the SIP to PSTN gateway,
That appears to me to be a problem of trading costs of different solutions.
What we have been deploying is a system in which you trust a third-party gateway to generate BYEs and send CDRs to you. The risk of having inaccurate CDRs depends on reliability and trustworthness of the third party. It seems to be an acceptable risk -- all in all it is CDRs what they get their money for.
You may wish to introduce an additional source of CDR in your system for sake of verification -- some kind of call stateful element which observes call status. However, the costs of such a solution do not appear to me to justify the benefits -- proxying media, keeping call state, interop issues with calls on hold or silence detection,and possibly more.
so all our calls are SIP:SIP without the possibility to check the gateway, if one side hang up it is likely that the other side will create a BYE, however if both sides are disconnected, we have a problem.
I am not sure if there is a value in a CDR for a call to a gatrway which exited abruptly.
-jiri