Wouldn't that then mean that calls from 991573 to 1488 wouldn't work either?
At the moment...
if I dial from 991573 to 1488 I can establish a call and have bidirectional audio.
if I dial from 1488 to 991573 I get ringing on the UCP but when I answer the call 1488 is diverted to VM.
If there was a protocol or codec issue I wouldn't have thought I'd be able to establish a call in either direction??
Thanks again for looking... I'm a bit of a noob really and extremely grateful of your help.