Performance Evaluation of Rate Adaptive Shapers in Transporting MPEG Video over Differentiated Service Networks

When transporting MPEG video streams over differentiated service networks, each stream will be assigned a traffic contract to which it has to be conformed to, to avoid packet loss and to preserve the displayed video quality. Video streams are bursty in nature due to the instant variability of the video content being encoded. To help mitigate the transport of bursty video streams with minimal loss of information, rate adaptive shapers (RAS) are usually used to reduce the burstiness and therefore help preserve the desired quality. In this paper we evaluate the performance of a proposed RAS technique in transporting MPEG video streams encoded at different rates. The performance is evaluated based on the two rate three color marking approach as described in [1]. In our evaluation approach we investigate the performance of RASs by considering and varying the following factors: First, the estimated incoming video rate and second, the choice of parameters used by the trTCM marker. The performance of the proposed RAS is compared with the use of no shapers and with the use of the trRAS described in [2, 7] to show its performance and effectiveness in controlling the burstiness of video streams.