Real-time networking over HIPPI

HIPPI provides a very-high-speed communication medium, which is very well suited for a large number of bandwidth-demanding distributed applications. Unfortunately, its circuit-switched nature makes it very difficult to provide real-time guarantees when connections contend for network resources. We present a time-division-multiplex access scheme designed to give timing guarantees to high-speed connections. We describe the problem of scheduling the access to a HIPPI network, and show that, although the problem is very unlikely to be computationally tractable, very simple heuristics give high network utilizations for moderately-sized networks. We present the RMP/RMCP protocol, our implementation of the scheme described in this paper on the XUNET-West HIPPI testbed