Multi-tree broadcast in peer-to-peer networks

Broadcast is a basic service for many network operations. It had been proposed to maintain a broadcast tree over a P2P network explicitly to support message broadcast from the root to leaves and information aggregation from leaves to the root reversely. We notice that 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 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 such a scenario, a peer near the root of one broadcast tree is probably a leaf of another tree. In this paper, a redirection mechanism, referred to as ABS, is used when multiple broadcast trees are maintained. Simulation results show that ABS 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.