I have a asterisk 13.11.2 PBX and a grandstream UCM61XX. I need to register a SIP extension from the asterisk PBX onto the Grandstream and also have a trunk between the two.
I can get both registered properly however my problem is identifying the endpoints.
You can’t have two “identify” sections matching the same address. There is no way to differentiate them because the matching is only done on the IP address.
I don’t know how the Grandstream PBX sends calls, but it may work. The problem is that it may not be designed/configured to allow both a trunk and an extension to the same device, so from the Asterisk side you can’t differentiate.