Patent ID: 8493875

Claim:
A monitoring system for monitoring the round trip time of data packets travelling between a first node and second node within a packet based network, the system comprising: a. A first module configured to interrogate traffic originating from the first node and to extract and store sequence numbers from individual packet headers; b. A timer module configured to initiate a timer on extraction of sequence numbers; and c. A second module configured to interrogate acknowledgements from the second node relating to the traffic sent, and to stop the timer on identification of an acknowledgment relating to a stored sequence number so as to provide an estimate of the round trip time of packets travelling between the first and second nodes; wherein the system is configured to effect, for each new acknowledgement, a comparison of the new acknowledgement with the stored sequence number and on identification of a situation where no prior timers are running for older outgoing sequence numbers to isolate the packet associated with that acknowledgement and mark the return trip time for that packet as being potentially inflated.