Fast Algorithms for Routing Around Faults in Multibutterflies and Randomly-Wired Splitter Networks
IEEE Transactions on Computers - Special issue on fault-tolerant computing
Wide-Sense Nonblocking Clos Networks Under Packing Strategy
IEEE Transactions on Computers
Optical crossconnects for high-capacity lightwave networks
Journal of High Speed Networks - Special issue on optical networking
Permutation Realizability and Fault Tolerance Property of the Inside-Out Routing Algorithm
IEEE Transactions on Parallel and Distributed Systems
An Analytical Model on the Blocking Probability of a Fault-Tolerant Network
IEEE Transactions on Parallel and Distributed Systems
Nonblocking WDM Multicast Switching Networks
IEEE Transactions on Parallel and Distributed Systems
Tolerating Multiple Faults in Multistage Interconnection Networks with Minimal Extra Stages
IEEE Transactions on Computers
The Mathematical Theory of Nonblocking Switching Networks
The Mathematical Theory of Nonblocking Switching Networks
Interconnection Networks for Multiprocessors and Multicomputers: Theory and Practice
Interconnection Networks for Multiprocessors and Multicomputers: Theory and Practice
Performance and fault tolerance improvements in the Inverse Augmented Data Manipulator network
ISCA '82 Proceedings of the 9th annual symposium on Computer Architecture
Literature survey of nonblocking network topologies
ICNVS'10 Proceedings of the 12th international conference on Networking, VLSI and signal processing
HiPC'05 Proceedings of the 12th international conference on High Performance Computing
Design and implementation of an on-chip permutation network for multiprocessor system-on-chip
IEEE Transactions on Very Large Scale Integration (VLSI) Systems
| Hi-index | 14.98 |
As optical communication becomes a promising networking choice, the well-known Clos network has regained much attention recently from optical switch designers/manufacturers and cluster computing community. There has been much work on the Clos network in the literature due to its uses as optical crossconnects (OXCs) in optical networks and high-speed interconnects in parallel/distributed computing systems. However, little attention has been paid to its fault tolerance capability, an indispensable requirement for any practical high-performance networks. In this paper, we analyze the fault tolerance capability of the three-stage rearrangeable Clos network. We first establish a fault model on losing-contact faults in the switches of the network. Then, under this model, we analyze the fault tolerance capability of the Clos network when multiple such faults present in switches in the input stage, middle stage, and/or output stage of the network. Our results show that the rearrangeable condition on the number of middle stage switches for a fault-free rearrangeable Clos network still holds in the presence of a substantial amount of faults, while a more expensive crossbar network cannot tolerate any single such fault. In particular, we obtain that, for an N \times N Clos network C(m,n,r), where N=nr and m \geq n, it can tolerate any m-1 losing-contact faults arbitrarily located in input/output stage switches, or any m-n losing-contact faults arbitrarily located in middle stage switches, when realizing any permutations. We also demonstrate that, for a given permutation, the network usually can tolerate much more such faults. We then present a necessary and sufficient condition on the losing-contact faults a Clos network can tolerate for any given permutation. We also develop an efficient fault-tolerant routing algorithm for a rearrangeable Clos network based on these results.