Deadlock-Free Routing Algorithms for 6D Mesh/iBT Interconnection Networks

As an application of interlaced bypass torus (iBT) interconnection networks, a 6D mesh/iBT network has been formed by replacing the 3D torus network in a 6D mesh/torus interconnect (Tofu) with a 3D iBT network, helping further reduce latencies. However, the routing algorithms good for the torus-based systems such as Blue Gene series may deadlock for the new network. This work proposes three deadlock-free routing algorithms for iBT networks and an optimizing method. An iBT network with these routings is simulated and compared with a 3D torus and a 4D torus network. Results for all-to-all communications, when applying the optimal routing algorithm, show a link utilization of 96% of the theoretical peak. An iBT prototyped system is also built and preliminarily tested.