Most of the tools available for monitoring multicast have only marginal utility in today's multicast infrastructure. These tools lack the ability to handle the latest routing protocols because they rely on application layer data like the Realtime Transport Protocol (RTP). Our goal is to develop a system that monitors multicast at the network layer; that can provide functionality for all of the network management tasks; and that can be easily extended to monitor the evolving set of multicast protocols. To this end, we have developed Mantra, a tool for collecting data from multicast routers, analyzing the collected data and presenting realtime results. Using collected data, Mantra creates interactive graphs depicting the state of the multicast infrastructure. Results from Mantra are being used to monitor multicast usage and deployment, as well as routing protocol deployment and performance. In addition, the results are being used to detect common anomalies and to troubleshoot frequent routing problems. In this paper, we discuss the issues related to multicast monitoring, describe the existing efforts in the field and present the design of Mantra. In addition, we present results based on data collected over a 6 months period by monitoring the multicast traffic at two points: (1) at the Federal IntereXchange-West (FIXW) router, and (2) an on-campus router.
['Prashant Rajvaidya', 'Kevin C. Almeroth']
A router-based technique for monitoring the next-generation of Internet multicast protocols