Patent ID: 7636321

Claim:
One or more tangible computer-storage media have computer-readable instructions embodied thereon for performing a method for computing the Round-Trip Time (RTT) of data packets flowing through a connection pathway having a beginning and an end, comprising providing a measurement point between said beginning and said end; maintaining a measuring point of the telecommunications pathway in a frozen state that persists as long as retransmitted data packets are consecutively received by the measuring point; receiving from a sender a new data packet that is destined for a receiver, determining that said packet includes a sequence number that is greater than or equal to another sequence number of a previously received packet; transitioning the measuring point to a default state that is usable to compute the RTT of the new data packet; passively measuring a first duration of time that spans: (1) from when the packet passes said measurement point to when it reaches its intended receiver; and (2) from when an acknowledgement corresponding to said packet's reception travels from said receiver to said measurement point; passively measuring a second duration of time that spans: (1) from when said corresponding acknowledgement travels from said measurement point to said sender; and (2) when a triggered packet travels from said sender to said measurement point; summing said first and second durations to compute a first RTT value; repeating said measuring and summing steps for subsequent packets to determine respective RTT values; and calculating an average RTT value by utilizing the determined RTT values and a total number of RTT values.