VBMAR: Virtual Network Load Balanced Minimal Adaptive Routing

Fully adaptive routing with less virtual channels is of technical trend in MPP interconnection network design. However, imbalance of load offsets performances of many schemes. In this paper we give a fully adaptive load balanced routing algorithm called VBMAR. A new design tool called crossed turn model (CTM) is proposed to solve complex deadlock problems across virtual networks while keep the load balanced. Non-deterministic finite automaton (NDFA) is used to model the routing process. The resulting algorithm features routing uniformity and channel priority. Concurrent architecture and parallel priority channel searching techniques are used in VBMAR router design, which make it cost efficient. Four algorithms are compared to evaluate the performance of VBMAR. Simulations show that VBMAR can considerably increase network throughput and shorten network delay under both uniform and nonuniform traffic patterns. We argue that VBMAR is a very competitive routing scheme for future commercial MPP systems.