I notice there are a number of other threads on this topic, but none of the proposed solutions are working for me.
My provisioned AG310 ATA starting smoking something serious last night, so rather than buy a new one, I switched to Open VFX and set up my Gigaset A580IP phone to make and receive calls. I can make calls but not received anything. All incoming calls go to voicemail.
Authentication name, password and username are set up correctly. Proxy server address is set to pan.wxnz.net. STUN is off. Registration refresh time is 180 seconds. Using port 5060.
Does the MAC address of the device need to be registered with Xnet? Is this a DNS issue? I'm using the DNS servers of my provider (I'm not an Xnet customer).