Impact of Traffic Shaping in ATM Networks on Video Quality

This paper presents the impact of traffic shaping on enhancing the interactive video quality over ATM networks. The effects of the leaky bucket traffic shaper on the video quality is studied under different token buffer rates and token buffer sizes, and the tradeoffs involved are discussed. An enhanced traffic shaper using the early drop mechanism is then introduced. Simulation results show that for delay sensitive applications like interactive video, the combination of traffic shaping and the early drop mechanism improves the video quality significantly compared to VBR video and regular traffic shaping. The influence of different traffic shapers on the cell loss and the cell loss distribution is studied and it is further explored how the cell loss distribution affects the video performance. The comprehensive study shows that the increase in video quality when using traffic shaping with the early drop mechanism comes both from reducing the cell loss and changing the cell loss distribution.