We have configured SIP trunk with 5 DID numbers. And incoming calls are routing to its destination based on Request-URI.
But we noticed that, For the incoming call from some telecom carriers, our sip trunk provider adding some junk character with its Request-URI. So that we lost those calls.
Correct Request-URI is 1234556@1.2.3.3 but sometime we got si123456@1.2.3.4 & 123456%23@1.2.3.4 for some telecom carriers(this was changed few times). We already reported this with them.
Is there any way to handle those calls if the PBX is received wrong Request-URI ? to send all those calls to an extension or to IVR ?