Patent ID: 7050465

Claim:
A system comprising two endpoints ( 1 , 2 ) communicating with each other by means of a packet-switched network, said endpoints ( 1 , 2 ) being adapted to estimate jitter from packet arrival times and to modify silence period lengths according to the latest estimate by using adaptation algorithms, wherein a response time (ρ) of the system is measured at a given time instant, the response time being defined as the time elapsed between the capture of a given frame of speech at one endpoint and its playout at the other endpoint plus the same quantity in the other direction, wherein: a first endpoint ( 1 ) is configured to send a response time request packet to a second endpoint ( 2 ) at a time s r ; said second endpoint ( 2 ) is configured to receive the response time request packet at a time r r ; said second endpoint ( 2 ) is configured to send a response time indication packet to said first endpoint ( 1 ) at a time s i ; said first endpoint ( 1 ) is configured to receive the response time indication packet at a time r i ; and said first endpoint ( 1 ) is configured to compute the response time (ρ) on the basis of the sending and receiving times, wherein the response time is used as a parameter in the adaptation algorithms, wherein the response time request packet sent from said first endpoint ( 1 ) includes information identifying one of the rackets which has been sent at a time s′ by said second endpoint ( 2 ) and received at a time r′ by said first endpoint ( 1 ) since its latest adaptation, and wherein the response time indication packet sent by said second endpoint ( 2 ) includes information identifying one of the packets which has been sent at a time s′ by said first endpoint ( 1 ) and received at a time r by said second endpoint ( 2 ) since its latest adaptation, and wherein said second endpoint ( 2 ) is configured to compute s′−s, and indicate the result in the response time indication packet.