I have recently just installed a UC520 with the T1/E1 card for my customers ISDN30 line. we can receive incoming calls perfectly OK but when we try to dial out we get a dial tone but then we get a message back from BT saying the number is not recognised. where am I going wrong.
I have installed another UC520 on another site although that one is only using the FXO ports for outgoing calls, this system works perfectly.
any pointers where I need to look would be greatly appreciated.