Statistical Characteristics of Multicast Traffic on a National Backbone Network

IP multicast catches Chinese researchers’ eyes recently as the deployment of non-tunnel multicast routing protocols throughout the CERNET mature. But characteristics of multicast traffic still need to be understood. Using our developed passive monitoring system, we observe multicast traffic on links connecting peer networks to our native multicast backbone network. First of all, we analyze of collected multicast traffic data on CERNET. Then we pursue a traffic traces collection over seven months. Comparing the experimental results with the analysis of unicast, we describe multicast traffic characteristics: packet size distribution, stream size distribution and address space distributions. We analyze the distribution of source numbers per group, peep into the content of multicast traffic and propose a hierarchical structure for carrying out our measurement and monitoring.