Has anybody had experience with a Verizon ISDN circuits in the UK?
I have an ISDN circuit provided by Verizon and another from BT.
As usual I manipulate the incoming CLI from the BT circuit to pre-pend '90' enabling the users to return calls from their call lists; '9' being for an outside line & '0' because BT never present the leading '0'!
I have tried to do the same on the Verizon circuit, they DO provide the leading '0' but I am trying to add a '9'. I have tried a h323 gateway as I use for BT and also tried an MGCP gateway by changing parameters in CUCM but neither will work.
Any ideas please?