Patent ID: 7016355

Claim:
A method for improving the quality of a voice call through a router controlled IP network that provides a segment of a telephone circuit for carrying information between at least two subscriber terminals, the method comprising: reacting to a request for a telephone circuit between said two subscribers by transmitting a voice packet containing an echo request message over the router controlled IP network from a first network node to a second network node; reacting to receipt of the echo request message at the second network node by transmitting a voice packet containing an echo reply message over the router controlled IP network from the second network node to the first network node; determining a round trip propagation delay for the router controlled IP network segment on the basis of the time which elapses between sending the echo request message from the first node and receiving the echo reply message also at the first node; and, introducing an echo cancellation mechanism into the IP network, as a function of said round trip propagation delay, prior to establishing said voice call.