Patent ID: 6904060

Claim:
A method for operating an interworking unit to hands user communications for a call from a first communication device, the method comprising: receiving a first control message into the interworking unit indicating a first identifier for routing the call to a second communication device wherein a user places the call using a telephone number for the second communication device and wherein a signaling processor selects the first identifier based on the telephone number and transfers the first control message to the interworking unit; receiving the user communications including voice communications into the interworking unit and in response to the first control message adding the first identifier to the user communications; transferring the user communications including the voice communications from the interworking unit with the first identifier for routing the call to the second communication device; after call setup and during the call, monitoring the user communication, to detect a call trigger; transferring a trigger message from the interworking unit if the call trigger is detected; receiving a second control message into the interworking unit indicating a second identifier for routing the call to a third communication device wherein the second control message is responsive to the trigger message; in response to the second control message, adding the second identifier to the user communications; and transferring the user communications including the voice communications from the interworking unit with the second identifier for routing the call to the third communication device.