Communication protocol for group of distributed objects

In distributed applications, a group of multiple objects are cooperated. On receipt of request messages, the objects send back the responses. The kinds of group communication protocols discussed so far, support the reliable and ordered delivery of messages at the network level. Only messages to be ordered at the application level, not necessarily all messages, are required to be causally delivered in the required order. The state of the object depends on in what order the requests are computed and the responses and requests are transmitted. In this paper, we would like to define the significant precedence order of messages based on the conflicting relation among the requests. We would like to discuss a protocol which supports the significantly ordered delivery of request and response messages.