Patent · US Expired

Method and system for accurately calculating latency variation on an end-to-end path in a network

US7333517B2 · kind B2 · utility

18Cited by
10References
16Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 12, 2005
Grant dateFeb 19, 2008
Priority date
Expiry dateAug 12, 2025

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04L12/2854
  • WIPO fieldDigital communication
  • WIPO sectorElectrical engineering

Abstract

A high-resolution, per-packet measurement tool for analyzing a computer network that operates by sending a predetermined number of packets from a sender machine to a receiver machine with measurement information inserted into the packet. The system kernel at the sending machine stamps a sequence number and the sender's local time into the data section of each packet. When packets arrive at the receiver machine, they are similarly stamped by the receiving machine's kernel with the receiving machine's local time. The maintained packet information serves as the basis for latency analysis. For example, one set of latencies can be obtained with QoS mechanisms turned on, and another set with QoS mechanisms turned off, whereby the benefits of the QoS mechanisms can be accurately determined. To analyze the latencies, the present invention normalizes each time and each latency into relative latency information. Clock skew and timer jumps may be handled as part of the normalization.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.