Message Broadcast Using Multiple Trees in DHT P2P Networks

Broadcast in P2P networking is a basic service for many operations. It had been proposed to maintain a broadcast tree over a DHT P2P network explicitly to support message broadcast from the root to all leaves and information aggregation from leaves to the root reversely. A peer near the root of a broadcast tree has shorter message latency and a smaller possibility of message loss due to join or departure of any peers in the path from itself to the root; however, it has to contribute more CPU power and network bandwidth to forward or aggregate messages. On the other hand, a leaf peer does not have to forward messages; however, it suffers from longer message latency and a larger possibility of message loss. A P2P network can maintain multiple broadcast trees to improve fairness. In this paper, a redirection mechanism, referred to as SABS, is introduced when multiple broadcast trees are maintained. Simulation results show that SABS further balances the load of peers and significantly reduces the minimal hop counts of intermediate peers that a broadcast message has to pass through before it arrives at a peer.