When working remotely and I change my Station Type to 'Remote Number' (Cell or land line) it will sometimes not connect calls to the remote number. The call will appear in My Interactions, but the state will stay in 'Initializing' for 30 seconds, then change to 'Disconnect [No Answer]. This can last for a few hours or even days. Sometimes restarting the Interaction Client will fix it, but usually not.

Be sure to specify the line to use for remote connections under the Default Station settings.

I know remote number station connections have been finicky in some SUs in 3.0. What version and SU of xIC are you on? As ShamusAngus mentioned setting the line group for external station connections usually fixes the issue. If this still does not work I would suggest you turn up logging on IP, Notifier, TS and SIPEngine to see what the server is trying to do when the the remote station connection fails.