Hi, everybody!
I need a help.
I have a router Cisco Catalyst 2921 (iOS version SPA.152-4.M5) working as a media gateway. the router receive SIP link from carrier and convert to PTSN (ISDN PRA link).
But i have a problem. The carrier send diferent causes Q.850 using the same cause in sip message. For example, calls when the destination send in SS7/ISDN a release cause 34 or cause 38, the carrier send for the router SIP 503 message.
I changed in the sip-ua mapping table, the sip status 503 to PSTN cause 34, but it's don't solve the problem. The equipment connected to PSTN link must receive the true cause to classify the call correctly.
The carrier support told me, inside the sip error messages they send the real Q.850 cause in field Reason and, my equipment must read this field to translate the real cause to ISDN.
How i make the router read this field? and translate the real cause to PSTN?
example of sip error messages received from carrier.
SIP/2.0 503 Service Unavailable
Via: SIP/2.0/UDP 10.255.121.12:5060;branch=z9hG4bK9cucrk20507gpggbc581.1
Call-ID: 4EAB84CA-4BAB11E7-88E4822D-CB736732@201.57.194.198
From: <sip:33046345@10.255.121.12>;tag=44D04FD4-142C
To: <sip:0216932183380@10.252.28.1>;tag=t767xubv
CSeq: 101 INVITE
Reason: Q.850;cause=34;text="no circuit available"
Warning: 399 - "SoftX3000 R601-CCU Rel POS:[14015] Release from CCB PP[0xe0] CS[0x4] AS[0x4] FR[0x8] TR[0x9] TYPE[0x2]"
Content-Length: 0
SIP/2.0 503 Service Unavailable
Via: SIP/2.0/UDP 10.255.121.12:5060;branch=z9hG4bKgnj8bl20c0j07hoor6c1.1
Call-ID: 5DD9A1B4-4BAB11E7-8BEA822D-CB736732@201.57.194.198
From: <sip:33046345@10.255.121.12>;tag=44D0B350-16EA
To: <sip:0216232739284@10.252.28.1>;tag=vubw43yy-CC-57
CSeq: 101 INVITE
Reason: Q.850;cause=38;text="network out of order"
Warning: 399 - "SoftX3000 R601-CCU Rel POS:[3] Release from CCB PP[0xe0] CS[0x8] AS[0x4] FR[0x8] TR[0x9] TYPE[0x2]"
Content-Length: 0
