Hello, I am wondering if there is anything in the RFC which describes how to properly handle responding to an INVITE for a number which is out of service. This mostly relates to SIP --> PSTN gateways. It seems like all carriers handle things a little differently, which makes dealing with these issues in a call center environment very challenging. Obviously everyone wants to know that a number is bad, but some of the carrier implementations make it almost impossible.
In my experience I have seen: Some respond with one or more 1XX followed by an appropriate 4XX error. Some respond immediately with a 4XX (no early media indicating the cause of the error) Some respond with only 1XX plus early media and never send final response. The UAC is forced to CANCEL. I have read through the RFC 3261 and it doesn't really cover this. Perhaps there is another RFC which more clearly maps out the PSTN/SIP interop. Thanks! Geoff _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
