The Java Reliable Multicast Service

Phil Rosenzweig
Boston Center for Networking
Sun Microsystems Laboratories


Multicast is a protocol which enables one to many communications for TCP/IP networks. Conceived in 1989, it is generally standardized and implemented in most internetworking equipment and hosts for TCP/IP networks. Although multicast does not guarantee delivery of data to all recipients, it is useful for applications such as streaming audio or video on local area networks. For example, "showmetv" is an application which uses multicast.

For applications which want to send mission critical business data to many recipients on global networks, multicast has the potential of being a much better transport than HTTP or TCP. However, reliable delivery must be added to the multicast protocol for this to be true.

Java Reliable Multicast Service (JRMS) is a SunLabs project in reliable multicast protocols and services designed for the Java environment. This talk describes the project, key technologies, applications, innovations and plans.

Technical report is available.


Phil Rosenzweig is Director of the Boston Center for Networking in Sun Microsystems Laboratories. He leads an advanced development group that focuses on new network protocols and services. Current projects include developing enabling technology for reliable IP multicast and a new public key security infrastructure. For the previous six years, he led Sun's PC Networking group where he was responsible for the PC-NFS product family of software products that provide connectivity between PCs and UNIX systems. Prior to Sun, Phil was Director of Software at Xyplex, where he helped develop one of the first multi-protocol communications servers. He has also held various engineering and management positions with Wang Laboratories, Data General and Burroughs Corp. Phil received a Bachelor's degree in Computer Science from Rochester Institute of Technology in 1977.

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