Fault tolerance property analysis for asymptotically minimal node-degree topology

Scalable routers can satisfy the urgent demand of rapid traffic increase on the Internet. However, link and node failures happen frequently thus fault-tolerance must be considered in the research and implementation of scalable routers. In this paper, we model fault-tolerant mechanism inside the scalable routers based on P2i (Plus 2∧i) topology of our prior work. P2i makes a tradeoff between performance and expansion cost. And it can expand at the minimal granularity while maintain the growth of scalable network diameter at O(log n). Based on this property, we provide a Fault-Tolerant Eigen Path (FTEP) routing algorithm. Using FTEP, we model the link and node failures of P2i and result shows that 100% throughput can be achieved when the speedup ratio equal to (k+2)/2 and k as the number of link failures.