We are trying to get some Aastra 6753 to register remotely. I know the remote location works ok (Loc B) - because we have tested iPhones there on Wi-Fi successfully. When I log into the device web-interface, I get registration status of 408 - which I think is Timeout and the display shows NO SERVICE. This location is using an Airport Extreme. In another remote location (Loc A), with a NETGEAR Wireless Router, we connect successfully to the 3cx server. We simply unplugged the device, and moved it to location B with the Airport and it can not connect. Any ideas? In my Wireshark - I show Loc B IP in Source to internal IP of 10.0.0.12 Protocol SIP - Request: Register sip:external ip at server:5060 This line is in there 4 times. I do indeed have WAN Access enabled for this extension as it was working at LOC A. Also -is it true that I need to keep port 5000 open for these devices to get updated config data and access MyPhone ?