I have a setup of CCM 5.1(3) and voice gateway. the voice gateway has NM-CUE module for voice mail. i have integrated the CCM 5.1(3) and UNITY EXPRESS using the integration document. cti route point and cti ports are gettting registered. But when i press the message button in IP Phone i am getting fast busy tone.
Configuration wise everthing done according to the document. What could be the problem.