A smoothing proxy service for variable-bit-rate streaming video

Provisioning network resources for multimedia streaming is complicated by the bursty, high-bandwidth traffic introduced by compressed video, as well as the variability of the throughput, delay, and loss properties of the Internet, and the lack of end-to-end control by any one service provider. To address these problems, we propose that proxies should perform online smoothing by transmitting frames into the client playback buffer in advance of each burst, to reduce network resource requirements without degradation in video quality. This paper describes the practical systems issues we have encountered in building a smoothing proxy service using off-the-shelf components, in the context of an MPEG-2/RTP streaming testbed.