Practical utilities for monitoring multicast service availability

Monitoring has become one of the key issues for the successful deployment of IP multicast in the Internet. During the last decade, several tools and systems have been developed to monitor several different characteristics of IP multicast. In this paper, we focus on one specific monitoring task: monitoring end-to-end multicast service availability in the inter-domain. This task is important to maintain service robustness between sources and receivers. Without this assurance, the multicast infrastructure may become disconnected and essentially unusable. In this paper, we first study existing multicast diagnostic tools (e.g. mping and mtrace) and present their shortcomings in verifying end-to-end multicast availability. Then, we propose new multicast diagnostic utilities (mcping and mcroute) that can be used to perform various monitoring and measurement functions including verification of end-to-end service availability. We present a sample case study demonstrating the utility of these primitives in detecting and classifying multicast reachability problems in the inter-domain. The proposed utilities introduce only a few modifications to the service architecture and, in exchange, provide the multicast community with effective means to monitor and measure multicast service characteristics.