Method and system for measurement of the delay through a network link bounded by an echo canceller

A method for measuring the delay through a network link bounded between a first and a second echo canceller comprising the steps of:

• determining a signal transmission time along a network path between a first endpoint and a second endpoint (tA), said network path including said network link bounded between said first and second echo cancellers;
• transmitting a first test signal from said first endpoint to said second endpoint through said network path;
• transmitting a first echo signal from said second endpoint to said first endpoint through said network path, said first echo signal simulating said first test signal;
• measuring a first minimum time delay between transmission of said first test signal and transmission of said first echo signal which causes said first echo canceller to cancel said first echo signal;
• transmitting a second test signal from said second endpoint to said first endpoint through said network path;
• transmitting a second echo signal from said first endpoint to said second endpoint through said network path, said second echo signal simulating said second test signal;
• measuring a second minimum time delay between transmission of said second test signal and transmission of said second echo signal which causes said second echo canceller to cancel said second echo signal;
• and
• calculating the delay through said network link bounded between said first and second echo cancellers based on said measured first and second minimum time delays and said determined network path signal transmission time (tA).

A system for measuring the signal transmission time through a network link bounded by an echo canceller comprising:

• a network path having a first endpoint, a second endpoint and a network link bounded by an echo canceller;
• a test apparatus connected to said first network path endpoint for transmitting a test signal from said first endpoint to said second endpoint through said network path;
• and
• a test apparatus connected to said second network path endpoint for transmitting an echo signal from said second endpoint to said first endpoint through said network path, said echo signal simulating said test signal,
• wherein said test apparatus connected to said first network path endpoint records a minimum time delay between transmission of said test signal and transmission of said echo signal which causes said echo canceller to cancel said echo signal, said minimum time delay being used to calculate the signal transmission time through said network link bounded by said echo canceller.