A Simple, Practical Distributed Multi-Path Routing Algorithm

We present a simple and practical distributed routing algorithm based on backward learning. The algorithm periodically oods scout packets that explore paths to a destination in reverse. Scout packets are small and of xed size; therefore, they lend themselves to hop-by-hop piggy-backing on data packets, largely defraying their cost to the network. The correctness of the proposed algorithm is analytically veriied. Our algorithm also has loop-free multi-path routing capabilities, providing increased network utilization and route stability. The Scout algorithm requires very little state and computation in the routers, and can eeciently and gracefully handle high rates of change in the network's topology and link costs. An extensive simulation study shows that the proposed algorithm is competitive with link-state and distance vector algorithms, particularly in highly dynamic networks.