Trade-offs in routing private multicast traffic

Multicast is a convenient and important mode of communication in internetworks, and there has been a number of studies on efficient routing of multicast traffic. In particular, simulation has been performed to evaluate the tradeoffs between source-specific trees and shared trees, and between various routing algorithms. We show that the consideration of security brings a new set of tradeoffs in routing private multicast traffic. We describe these trade-offs between security, trust, knowledge of group membership and of topology, types of multicast tree, bandwidth consumption, and latency. We propose four methods to improve efficiency: message pruning, message reprocessing, hot-start authentication, and continuous authentication. This study of new trade-offs helps in choosing the appropriate multicast strategies for specific applications.