I am working on setting up a trunk on my 3CX system with a Generic Trunk. Our provider allows us to use multiple DIDs through the same account however the way they deal with mutiple PBXs is to set the User ID in the trunk registration to the specific DID. We have multiple PBXs in house so each will have its own DID through the same trunk. In 3CX we dont seem to be able to set a specific User ID for the trunk just the Authentication ID so the registration isnt working. If we try and register on the main trunk it works just fine. In Asterisk for example we can set the User ID and Authentication ID separately. Any thoughts?