Tracetree: a scalable mechanism to discover multicast tree topologies in the Internet

The successful deployment of multicast in the Internet requires the availability of good network management solutions. Discovering multicast tree topologies is an important component of this task. Network managers can use topology information to monitor and debug potential multicast forwarding problems. In addition, the collected topology has several other uses, for example, in reliable multicast transport protocols, in multicast congestion control protocols, and in discovering network characteristics. We present a mechanism for discovering multicast tree topologies using the forwarding state in the network. We call our approach tracetree. First, we present the basic operation of tracetree. Then, we explore various issues related to its functionality (e.g., scalability, security, etc.). Next, we provide a detailed evaluation by comparing it to the currently available alternatives. Finally, we discuss a number of deployment issues. We believe that tracetree provides an efficient and scalable mechanism for discovering multicast tree topologies and therefore fills an important void in the area of multicast network management.