An Euler Path Based Technique for Deadlock-free Multicasting

The existing algorithms for deadlock-free multicasting in interconnection networks assume the Hamiltonian property in the networks topology. However, these networks fail to be Hamiltonian in the presence of faults. This paper investigates the use of Euler circuits in deadlock-free multicasting. Not only are Euler circuits known to exist in all connected networks, a fast polynomial-time algorithm exists to find an Euler circuit in a network. We present a multicasting algorithm which works for both regular and irregular topologies. Our algorithm is applicable to store-andforward as well as wormhole-routed networks. We show that at most two virtual channels are required per physical channel for any connected network. We also prove that no virtual channels are required to achieve deadlock-free multicasting on a large class of networks. Unlike other existing algorithms for deadlock-free multicasting in faulty networks, our algorithm requires a small amount of information to be stored at each node. The potential of our technique is further illustrated with the help of various examples. A performance analysis on wormhole-routed networks shows that our routing algorithm outperforms existing multicasting procedures.