Modeling of Packet Loss and Delay
and Their Effect on Real-Time Multimedia
Service Quality
Wenyu Jiang & Henning Schulzrinne
Columbia University
Abstract:
Internet packet loss and delay exhibits temporal dependency.
If packet n is lost, packet n + 1 is also likely to
be lost. It leads to bursty network losses and late losses
in real-time multimedia services such as Voice over IP
(VoIP). This may degrade perceptual quality and the effectiveness
of Forward Error Correction (FEC). To characterize this burstiness, we first discuss the modeling of
packet loss and delay. We propose the joint use of the extended
Gilbert model and the inter-loss distance (ILD)
metric to characterize temporal loss dependency. For delay, we
introduce a metric called the conditional cumulative
distribution function. We have applied these models
to some Internet packet traces to validate the necessity
and effectiveness of these models. We then evaluate the
effect of these dependencies on VoIP by investigating
the final loss pattern (FLP) after applying playout delay
adjustment and FEC. Our results through a set of
simulations confirmed that the FLP is still bursty.