Deadlock-free connection-based adaptive routing with dynamic virtual circuits

Virtual circuits can reduce routing overheads with irregular topologies and provide support for a mix of quality of service (QOS) requirements. Information about network loads and traffic patterns may be used during circuit establishment to utilize network resources more efficiently than is practical with packet routing. Most virtual circuit schemes are static — each established virtual circuit remains unchanged until the connection is no longer needed. In contrast, we propose the Dynamic Virtual Circuit (DVC) mechanism, which enables existing circuits to be quickly torn down in order to free up resources needed for other circuits or to re-establish circuits along routes that are better suited for current network conditions. We propose a deadlock avoidance technique, based on unconstrained routing of DVCs combined with a deadlock-free virtual network. We present a correctness proof for the scheme, describe key aspects of its implementation, and present performance evaluation results that explore its potential benefits.