I have been working with a customer for the last few months, trying and failing to get the system they want to work. They have a central site and a remote site, each with a SIP Trunk fed from a TA908E. In the past, if one company has multiple locations, they would have two separate trunks with two separate PBX systems and the redundancy for them is handled on the backend by our carrier. This customer has a Mitel MiVoice located at the central site that the remote site is supposed to feed back to. The central site currently works without issue, but we are having various issues with getting the remote site to cooperate. When watching the debug, calls will either not work and give a 404 not found error in the invite, or it will process correctly, and the customer relates that direct inward dialing to the pilot number of the remote sites' trunk ends up going to the central sites' trunk. Both sites have been tested independently on our end with a T-BERD and they work fine. Only once we introduce their (weird imo) setup does it have issues. I can't imagine that since both sites work while testing from our end that there is any issue with the 908E configs.
What is also strange, is that when dialing from the pilot of the remote site, we see the call flow path on both of the 908Es debug(Central and remote).
Here's a description of the customer's network infrastructure:
Adtran<>Remote MBG<>Central MIVB<>VPN<>IP Phones
"There is a virtual infrastructure in the remote location that we have our Mitel Border Gateway on that is at IP address X.X.X.X which we then use a SIP connection to connect to your equipment at X.X.X.X. From the central location where the virtual MiVoice Business system is located with an IP address of X.X.X.X we setup a network element that points to our Mitel Border Gateway in the remote site as a proxy and also a network element to your equipment address. We then setup a SIP Peer Profile to setup the connection between the remote phone system that goes across their VPN and connects to the virtual Mitel Border Gateway that then connect to you."
Anyone with experience with both 908Es and PBX systems would be very helpful. I can attach the 908E configs if necessary.
Thanks