External fordwarding Identification

[dvid9976]

hello there

I'm experiencing some problems since one of our Telco decided to replace their traditional ISDN E1 with SIP-E1 Gateways (SIP on telco's network, still ISDN to OXE).
- External users XXXXX dials an OXE's DDI.
- OXE extension is diverted to a mobile number YYYYYY
- When using traditional IDSN, on my mobile YYYYY screen I receibed XXXXX number (good, because I kwnow who is calling)
- When using ISDN-SIP Gateway on my mobile YYYY I receibed a ZZZZZ number, which is being inserted by the telco gateway (not good, I don't know who is calling)

Telco says that using SIP, they cannot not progress a call with XXXXX as calling number, since it is not an authorized calling number on their circuits and only the customers DDIs are allowed as calling originating numbers.
They ask a kind of indication that the call is being fordwarded so the sip gateway can understand the scenario and translate accoringly in a different field that is not the calling number,

I have done many traces and found that for external fordward, what OXE makes in reallity is a second call with calling XXXXX, called YYYY but cannot find any indication that the call is an external fordward or similar.

Do any of you faced this issue?

thank you

[frank]

Hi,

Check P-Asserted-Identity
Usually, the carrier replace the caller ID with this info, in case of call forwarding, typically like in your scenario.