Analysis of Ant Colony Optimization-based routing in optical networks in the presence of byzantine failures

Byzantine failures during the execution of the routing algorithm may degrade or disrupt the normal operation of the network. Ant Colony Optimization (ACO)-based routing algorithms are especially vulnerable to those failures. In this work, we propose the use of crankback re-routing extensions associated to the ACO algorithm in wavelength-routed optical networks to deal with byzantine failures. We investigate three different byzantine failure scenarios: misdirection of forward ants, dropping of forward ants and dropping of backward ants. Those failures affect the routing information of the network, but they are very hard to detect and cannot be fully addressed by integrity and authentication techniques. Without any need for a byzantine failure detection mechanism, simulations have demonstrated that the proposed approach is effective in mitigating the impact on the blocking probability due to network nodes exhibiting a byzantine behavior.