unique trunks authentication id

[manfer]

Why two trunks can't have same authentication id?

 

[YiannisH_3CX]

Hello @manfer

Please note that the Auth ID of each trunk is used for source identification so that the PBX can match the call to a trunk. That is why it has to be unique for each trunk. The way source identification works is explained in detail here: https://www.3cx.com/docs/sip-trunk-inbound-calls/

 

[manfer]

Hello @YannisH_3CX

I match by "Request Line URI: User Part" which is not the trunk "SIP Authentication ID".

If my INVITES "Contact: User part" are not "Auth ID", which is not mandatory as far as I know, that match criteria is not applied.

And anyway, shouldn't 3CX PBX be clever enough to know which trunk is comming the INVITE from by IP as the very first match criteria? It is already configured on the trunk itself by IP or by domain. I can be wrong but I don't see the need of that unique Auth ID constraint.

 

[YiannisH_3CX]

As you may have seen in the document i quoted there are many different ways the PBX uses to match the call with the trunk. Since the Auth ID is one of them you cannot use the same on 2 trunks. You can set the PBX to match the IP the invite is coming from to the IP of the registrar but you need to know that those 2 match. The PBX does not do that automatically as many providers have multiple servers with different IPs. The signalling server may have one ip where the media server another.