Patent ID: 8218576

Claim:
A method for generating a one-way latency profile between a first computer node (A) having a first clock and a different second computer node (B) having a second clock, located in a data network without continuous clock synchronization, comprising: pre-synchronizing said first clock of said first computer node (A) with said second clock of said second computer node (B) to generate pre-synchronization values representing one or more absolute clock values and one or more clock difference values, following said pre-synchronizing, collecting a predetermined number of time measurements, following said collecting, post-synchronizing said first clock of said first computer node (A) with said second clock of said second computer node (B) to generate post-synchronization values representing one or more absolute clock values and one or more clock difference values, interpolating said time measurements with said pre-synchronization values and said post-synchronization values to create a predetermined number of latency measurements, and generating said one-way latency profile based on said latency measurements, wherein said pre-synchronizing comprises: sending a first predetermined message N times from the first computer node (A) to the second computer node (B), receiving at the first computer node (A) one or more second predetermined message sent by the second computer node (B), generating N round-trip-time items according to T i.4 −T i.1 −(T i.3 −T i.2 ), where i is in the interval [1 . . . N], and T i.1 is the sending time of the first predetermined message, T i.2 is the receiving time at the second node (B) of the first predetermined message, T i.3 is the sending time of the second predetermined message, and T i.4 is the receiving time at the first computer node (A) of the second predetermined message, generating N offset items, retrieving a minimum round-trip-time item within the N round-trip-time items, setting said clock difference value to the offset related to the minimum round-trip-time item, and setting said absolute clock value to T i.4 for the i having the minimum round-trip-time item.