System for establishing and maintaining a clock reference indicating one-way latency in a data network

摘要

A method for indicating one-way latency in a data network, with continuous clock synchronization, between first and second node having clocks that are not synchronized with each other includes a continuous synchronization session and a measurement session. The method repetitively sends predetermined synchronization messages from the first node to the second node and from the second node to the first node, calculates a round trip time for each message at the first node, updates a synchronization point if the calculated round trip time is smaller than a previously calculated round trip time, stores the updated synchronization points of a synchronization window, and calculates a virtual clock from the updated synchronization points of the synchronization window. The measurement session collects multiple measurements of one-way latency between the first and second nodes using the virtual clock, and generates a latency profile by interpolating the multiple measurements.

主权项

1. A method for measuring one-way latency in a data network, between a first node and a second node, each node coupled with a first and second clock respectively and where the first and second clocks are not synchronized, comprising:
sending predetermined synchronization messages from the first node to the second node and from the second node to the first node; calculating a round trip time for each synchronisation message at the first node; updating a synchronization point if the calculated round trip time is smaller than a previously calculated round trip time; calculating a virtual clock from the updated synchronization point of a synchronization window; collecting multiple measurements of one-way latency between said first and second nodes using the virtual clock; and generating a latency profile based on said multiple measurements.