Patent ID: 7167486

Claim:
A method of communication between at least two private branch exchanges including a source private branch exchange and a destination private branch exchange, the method comprising: sending a first media stream from the source private branch exchange to a first port predetermined for media streams at the destination private branch exchange; sending a first control stream from the source private branch exchange to a second port predetermined for control streams at the destination private branch exchange; wherein the first control stream comprises a first unique identifier of the first media stream; wherein the first port and the second port have port numbers different from each other; sending a second media stream from the destination private branch exchange to a third port predetermined for media streams at the source private branch exchange; sending a second control stream from the destination private branch exchange to a fourth port predetermined for control streams at the source private branch exchange; wherein the second control stream comprises a second unique identifier of the second media stream; and wherein the third port and the fourth port have port numbers different from each other.