Using passive measuring to calibrate active measuring latency

Abstract

The network performance obtained from the active probe packets is not equal to the performance experienced by users. We can obtain more exact result by using the characteristics of packets gained by passive measuring to calibrate the result of active measuring. The method of combining passive and active approaches has some advantages such as protocol-independent, negligible extra traffic, convenience and being able to estimate individual user performance. Considering the number of user data packets arriving between probe packets and the latency alteration of neighborhood probe packets, we propose the Pcoam (Passive Calibration of Active Measurement) method. It could reflect the actual network status more exactly, especially in the case of network congestion and packet loss, which has been validated by simulation. © Springer-Verlag Berlin Heidelberg 2005.