Multicast Group Communication for CORBA

Multicast group communication is a useful augmentation to CORBA both for fault-tolerant and highly available applications and for groupware and cooperative work applications. However, different multicast group communication protocols are appropriate in different environments, e.g., local area vs. wide area networks, and Internet vs. ATM. In this paper we present a multicast group communication engine and bridge for CORBA that allows different multicast group communication protocols to cooperate. The group communication engine places Lamport timestamps on messages, and multicasts messages to object groups using one or more group communication protocols. The group communication protocols reliably deliver the timestamped messages in timestamp order to the group communication engine, which integrates these streams of messages into a single stream for delivery in timestamp order.