In the physical design of integrated circuits, routing is the process of creating physical signal connections from logical connectivity requirements under various design constraints. Based on a previously constructed placement of the circuit elements, and on a graph that describes the fundamental communication structures and capacities, global routing is applied to solve the problem on a high level, with details of refinements, adjustments, and corrections left to later design phases.

Regular contests based on widely accepted benchmark suites will help advance the state of the art in global routing. Thus, the International Symposium on Physical Design (ISPD) has developed a Global Routing Benchmark Suite that is described in this short paper. Based on previously constructed placement benchmarks, eight global routing benchmarks were developed for a contest at ISPD 2007; these were extended by another eight benchmarks for the ISPD 2008 contest. The suites were carefully chosen to comprise benchmarks with different characteristics with respect to, for example, the number and nets to be routed, the structure of the global graph, and the capacities of the edges, thus yielding a number of representative problem instances.

The paper offers a clear overview of the design rationale of the benchmarks, and also discusses the problem of choosing a metric for comparing the quality of solutions; essentially, both contests emphasized congestion reduction, with the number of overflows as the primary objective function. Together with the ISPD placement benchmark, the global routing benchmark is certainly going to foster future research in physical design.