ATT is no help, they say they support 3CX but they have no info on setup. Has anyone had luck with this SIP provider.. We cannot get outgoing calls to work at all. Wireshark trace shows connection refused at the ATT IP address, incoming calls are fine. Not a routing issue on my side the request it getting to the provided IP. They are saying there is no authenticatioin, the physical connection to the ATT cisco router is the authentication.. Of course they give you 4 IP address 2 signalling and 2 media, you have to set up separate trunks to use all and I have a separate NIC hooked strait to a Cisco Router that is how they hand of the SIP service not over the internet connection. See attached wireshark Any thoughts would be greatly appreciated..