Patent ID: 7295559

Claim:
A method for recovering a service clock through a packet network for the provision of isochronous services, comprising: providing first and second stable local oscillators at respective transmitting and receiving nodes; generating first timing information about said first stable local oscillator; transferring said first timing information from said transmitting node to said receiving node over the packet network without reference to a common network clock; using said first timing information received at the receiving node to control the second stable local oscillator based on long term averaging of the frequency difference between the first and second stable oscillators; generating second timing information relating said service clock to said first stable local oscillator at said transmitting node using said first stable local oscillator as a reference for said second timing information at the transmitting node; transferring said second timing information from said transmitting node to said receiving node; and recovering said service clock at the receiving node from said second timing information and said second stable local oscillator using said second stable oscillator as a reference for said second timing information at the receiving node.