Core discovery in Internet multicast routing protocol

This paper presents modifications to the Core Based Tree (CBT) multicast routing protocol for selecting a set of optimal routers in a domain as core routers for a multicast group. Currently, there is no mechanism in CBT to locate core routers in an automatic fashion, adapting to network changes. Our proposed modifications help configure an optimal router as core based on three heuristics: Center of Members (CBT-CoM), Center of Sources (CBT-CoS), and Center of Sources and Members (CBT-CoSM). We next evaluate and compare the performance of these heuristics using network dynamics. For this, an implementation based on the simulation package NSv2 and a topology generation package GT-ITM is considered.