Experimental study of unicast and multicast video traffic using WAN test bed

摘要

The deployment of IP multicast protocols in each router in the path is needed to access the benefits of the multicast. IP multicast exists today mainly in LAN networks and in small areas of highly controlled interconnected networks. In fact, some companies started to offer tailored solutions to try to overcome these limitations. On the other hand, over the last decade, the multimedia applications have expanded rapidly, and in particular in video applications. There are Internet sites that offer movies on-line; and it is common for users to upload and download videos with sites like YouTube (© Google Inc.). The video call via the Internet is common with applications, such as Skype (© Microsoft). The growth of video traffic should be taken into account when designing a network. Understanding the behavior of the video traffic and the requirements for the network helps network administrators to improve the traffic planning. In this work, a quantitative analysis is performed by experimentation, in order to evaluate the behavior and impact of video traffic on WAN networks. We propose a WAN test bed composed by a video traffic server and several client stations that allows injecting unicast and multicast video traffic, compressed with several codecs. From capturing video traffic, we identified several interesting unicast and multicast performance metrics, such as: throughput, number of frames, delays, jitter, and interframe spaces and frame sizes distributions. Several factors have been taken into account: the video resolution configuration, the type of video, and restrictions on the bandwidth, as in a corporate real WAN link of some few Mbps. This study facilitates the comparison of the results with those obtained from analytical and modelling studies for different contexts.