Impact of ATM cell delay on multimedia applications

The impact of ATM cell delays on multimedia application performance is stud ied through measurements using a broadband network analyser. A method is de veloped to measure the ATM cell delays of an application using the analyser . It is found that the cell delay distribution becomes continuous as the tr affic load on a connection becomes lighter. The effect of background traffi c on cell delay for a reference connection is studied. Though the cell dela y of the reference connection is unaffected by the presence of background t raffic, the cell-delay auto-correlation is found to decrease. A gamma distr ibution is used to approximate the cell delay distribution. The measurement results closely match the delay prediction using the approximation. In a n etwork with multiple ATM switches, the gamma distribution only slightly ove restimates the delay. The frame level statistics and the cell delay perform ance of a video conferencing application based on motion JPEG are measured. Using the gamma cell delay distribution, the frame loss of an MPEG-I video source is predicted and compared against the measured values based on MPEG -I traces. (C) 2000 Elsevier Science B.V. All rights reserved.