Wormhole routing networks have become increasingly popular for low latency, high-speed interconnection
of supercomputer and workstation clusters. An example is the Supercomputer SuperNet
(SSN) at UCLA, which interconnects supercomputers across campus and metropolitan area
distances. SSN employs a two-level network architecture in which an optical backbone network interconnects
several high-speed, wormhole-routing local area networks (Myrinets). SSN applications
such as scientific visualization and rendering require that the network support reliable delivery of
traffic characterized by Quality of Service (QoS) parameters. Motivated by this requirement, we
investigate QoS support in Myrinet-like high-speed, wormhole routing networks. Since these networks
do not provide QoS support, we explore several novel strategies including (a) the use of a
separate subnet for carrying such traffic (along with the use of pacing), (b) superimposing a virtual
synchronous system on the asynchronous network, and (c) employing virtual channels to provide
QoS support while integrating QoS traffic and non-QoS (or datagram) traffic on the same network.
We discuss the tradeoffs among the different options and evaluate them via selected simulation
experiments.