A multicast transport driver for Globus XIO

In recent years, much work has been done on attempting to scale multicast data transmission to hundreds or thousands of receivers. There are, however, many situations where an application might involve transmission to just ten or twenty sites. Today's grid environments, for example, see high energy physicists carry out multi-gigabyte bulk data transfers to a handful of destinations. In this project, we are investigating how TCP-XM, a modified version of TCP that supports multicast, can be integrated with Globus to to provide grid users with a reliable multicast transport protocol. Our approach has been to use Globus XIO - an extensible input/output library for Globus that provides a POSIX-like API to swappable I/O implementations. We have wrapped TCP-XM in XIO to extend Globus to support multicast transmission. This paper describes the implementation and operation of our Globus XIO multicast driver, reviews the TCP-XM protocol design, and provides some experimental results.