Sip trunk with register base

[mbashar89]

When I create sip trunking with register base between 3cx and sbc, I it working well when calls go out using trunk number as outbound caller ID but don't work when using extension ID as outbound caller number. When I capture I see that 3cx send invite without registration and sbc replay with 401. I my question can 3cx use sip trunking credential for any different outbound caller ID?

 

[ClsVip]

I don't think your problem is with 3cx, and with registration-based providers, in a normal scenario, the PBX sends an invite to the provider to which they will reply with a 407 proxy authentication required, and another invite is sent from the PBX to the provider with the authentication digest, and the call continues, The registration details set under the authentication section of the trunk do not change and if you are seeing a 401 form the provider when trying to send another number, other than the main trunk number, then the question is, what is set under the outbound parameters of the trunks settings, for the From user part sip filed if auth ID then you can not change it as this is required to authenticate.

Suggests checking with the provider to be sure.