The paper studies the impact of OXC equipment failure in WDM networks with dynamic end-to-end optical circuit provisioning. At the OXC level, equipment reliability is calculated using proven component level reliability models. At the network level, end-to-end optical circuits are provisioned with various levels of reliability, thus
offering differentiated reliability to applications. The desired reliability level is obtained via shared path protection (SPP) switching, that provides efficient resource utilization. A selection of representative OXC architectures is examined to assess the influence of various switching technologies on the overall network level reliability. The selected OXC architectures are compared in terms of both the cost of switching equipment and the ability of the
network to accommodate incoming circuit requests, while satisfying their required reliability level.