Performance evaluation of 10Base-T and 100Base-T Ethernets carrying multimedia traffic

摘要

The performance of 10Base-T and 100Base-T Ethernet segments carrying audio/video traffic is presented. End-to-end delay requirements suitable for a wide range of multimedia applications are considered (ranging from 20-500 ms). Given the specific nature of the network considered and the maximum latency requirement, some data is lost. Data loss at the receiver causes quality degradations in the displayed video in the form of discontinuities, referred to as glitches. We define various quantities characterizing the glitches, namely, the total amount of information lost in glitches, their duration, and the rate at which glitches occur. We study these quantities for various network and traffic scenarios, using a computer simulation model driven by real video traffic generated by encoding video sequences. We also determine the maximum number of video streams that can be supported for given maximum delay requirement and glitch rate. We consider various types of video contents (video conferencing, motion pictures, commercials), two encoding schemes (H.261 and MPEG-1), and two encoder control schemes [constant bit rate (CBR) and constant-quality variable bit rate (CQ-VBR)] and compare their results. Furthermore, we consider scenarios with mixtures of video and data traffic (with various degrees of burstiness), and determine the effect of one traffic type over the other.