How is delay variation (jitter) measured? Print
Written by Максим   
Tuesday, 11 January 2011 13:50
Delay variation  (Jitter) is calculated during tests according to RFC 3550 method:

Ji = Ji-1 + (|Di-1,i| - Ji-1)/16

Where
  • Ji – measured delay variation at i-th iteration.
  • Di-1,i – difference of receiving times of two consecutive test requests.

Di-1,i = (Ri-1 – Si-1) - (Ri - Si)

R – test request generation time,  S – test request receive time.

During U7-type (UDP-echo) test the variation of round-trip time is measured, using the local time of originating IQM agent.
During U0-type test the variations of one-way trip delays are measured in both directions. Originating agent’s local time is used for test timestamp, receiving agent’s local time is used for packet delivery time.

Last Updated on Tuesday, 11 January 2011 14:35