To extend the widespread use of the high performance parallel interface (HIPPI) as a networking solution for high-speed communications, the 25-meter distance limitation must be solved. Three options available for alleviating the problem of distance limitation are serial-HIPPI, HIPPI/SONET mapping or HIPPI-ATM mapping, and IP routing. Serial-HIPPI, HIPPI/SONET mapping and HIPPI-ATM mapping provide extended HIPPI connectivities at the physical layer, while IP routing forwards data between the HIPPI networks and other networks at the network layer. We study two feasible solutions of this problem, HIPPI tunneling (HIPPI-ATM mapping) and IP routing. We compare these two schemes in terms of network connectivities, protocol overhead, and flow control. The performance evaluation of one implementation of HIPPI tunneling and IP routing is presented. The experimental performance suggests that a high degree of bandwidth utilization was achieved by both HIPPI tunneling and IP routing in this implementation.

ATM has been widely accepted as the key enabling technology for emerging multimedia applications. We at the Honeywell Technology Center are investigating the application of this technology to real-time control systems. The Mercuri wide area ATM testbed is a collaborative research effort in this direction. In this paper we describe our experiences from a series of performance evaluation experiments on the Mercuri testbed. Besides measuring application level throughput and round-trip delay, we investigated the support for real-time provisions like priority and deadline guarantees, which are especially important for control applications. We also measured delay and jitter for remote video transfer under no-load and loaded conditions. The major conclusion of our experiments is that the end systems remain a major bottleneck for high speed communications. We point out possible causes of performance degradation in this paper and outline some issues that need to be resolved for ATM to become a viable alternative for real-time multimedia based control applications.

Describes the traffic characteristics of the HDDL (High Definition Distance Learning) ATM Trial. Specific attention is focused on the ATM cell traffic patterns for audio, video, and data.