REAL-TIME CAUSAL MESSAGE ORDERING IN MULTIMEDIA SYSTEMS

Messages that are sent to and received by multiple sites need to have a consistent order imposed by all sites. Causal ordering allows the ca use and effect relations of messages to be maintained. This paper pres ents an algorithm that ensures that multimedia data with real-time dea dlines are delivered to the application layer in causal order. The alg orithm is designed to ensure that any message that arrives at a destin ation site before its deadline will be delivered to the application be fore the message expires. In addition, by focusing on a form of causal ordering violations caused by ''the triangle inequality'', this algor ithm has a low overhead with respect to the amount of information that must be appended to each message.