Question for the experts: We have a scenario where a SIP user originates a call to the PSTN (not 9-1-1) with a SIP From: header containing one DID and P-Asserted-Identity showing a different DID. We expect the carrier to use the P-Asserted-Identity for billing and recordkeeping but send the SIP From: out as the CLID to be displayed to the called party. Typically this is done in a call center type scenario where an agent wants the CLID to display the main number of the agent pool and not the specific DID of the agent. Another scenario is a customer PRI-based PBX that hairpins inbound calls back out to a traveling user and wants to preserve the original caller's information. One of our terminating carriers uses the P-Asserted-Identity as the displayed CLID and not the SIP From:. I feel that this is not correct. Opinions? Numbers have been changed to protect the guilty... TO: <sip:8055550123 at www.xxx.yyy.zzz;user=phone> FROM: "Fred Flintstone"<sip:+18055550199 at www.xxx.yyy.zzz;user=phone>;tag=1689985881-1343063740200- P-Asserted-Identity: "Fred Flintstone"<sip:+18055550177 at www.xxx.yyy.zzz;user=phone> TIME/DATE: Mon Jul 23 17:15:39 2012 (GMT) RESULT: Called party (8055550123) is seeing 8055550177 as calling party's caller ID instead of 8055550199 -- -- Jay Hennigan - CCIE #7880 - Network Engineering - jay at impulse.net Impulse Internet Service - http://www.impulse.net/ Your local telephone and internet company - 805 884-6323 - WB6RDV