An ordered and reliable broadcast protocol for distributed systems

The purpose of a reliable broadcast protocol is to allow groups of nodes on unreliable broad cast networks to reliably broadcast messages A reliable broadcast protocol must guarantee two properties all of the receivers in a group receive the broadcast messages and each of the receivers orders the messages in the same sequence In an optimistic approach to reliable broadcast protocol a batch acknowledgement is employed for a sequence of broad cast messages instead of one or more acknowledgement per broadcast message used in the pessimistic approach In this paper based on the optimistic approach we have proposed a counter based reliable broadcast protocol In this protocol the unique token ownership is circulated among all the nodes in an order speci ed by a token passing list The system state which records related information about messages broadcast by each node is included in the token message By appropriately updating the counter information recorded in the system state included in the token message instead of using explicit acknowledgement mes sages the proposed protocol needs fewer control messages to commit a broadcast message than other protocols no matter the rate of transmission errors is high or low Moreover we show how to handle the ow control problem and the token update technique