Connection-based Adaptive Routing Using Dynamic Virtual Circuits

Virtual circuits can reduce the routing overhead with irregular topologies and provide support for a mix of quality of service (QOS) requirements. Information about the state of the network and expected 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 — once the circuit is established, it remains unchanged until the connection is no longer needed. The Dynamic Virtual Circuit (DVC) mechanism allows existing circuits to be quickly torn down in order to free up resources needed for other circuits or in order to be reestablished along routes that are better suited for current network conditions. We present a deadlock avoidance technique, based on unconstrained routing of DVCs combined with a deadlock-free virtual network. We describe key aspects of the implementation of our scheme and present performance evaluation results that explore its potential benefits.