Patent ID: 7079554

Claim:
A method for synchronizing transmission of real time synchronous data packets over an asynchronous network between at least two terminal nodes using an intermediating communication device which connects between the terminal nodes TDM equipment and the asynchronous network, wherein communication devices comprise internal local clocks which are each activated by a stratum pulse generator, wherein local clocks are synchronized by utilizing transmission or reference timestamp packets through the asynchronous network and using an internal digital phase locked loop (DPLL) for attenuating jitter and wander in a data transmission signal in accordance to stratum accuracy standards, wherein the synchronization procedure of the local clocks comprises the steps of: a. transmitting a timestamp, at a low layer through the asynchronous network; b. receiving incoming data packets from the asynchronous network at the receiver terminal node; c. identifying a timestamp packet of a transmitting station among the incoming data packets, and extracting a remote timestamp of the timestamp packet; d. calculating a difference between the remote timestamp, which originated in the network, and a local timestamp, and using the calculated difference as an input to the DPLL; e. attenuating jitter and wander in data transmission signal by the DPLL, in accordance to the stratum accuracy standards; and f. outputting a DPLL output result as a new reference for generating a next timestamp.