Reliability and efficiency are important criteria in the design of interconnection networks. Connectivity is a widely used measurement for network fault-tolerance capacities, while diameter determines routing efficiency along individual paths. In practice, we are interested in high-connectivity, small- diameter networks. Recently, the w-wide diameter dw(G), (w - 1)-fault diameter Dw(G) and the w-Rabin number rw(G), for w ≤ k(G) have been used to measure network reliability and efficiency. In this paper, in addition to these pa- rameters we introduce (w-1)-fault wide diameter Pw(G) and study these parameters for the undirected circulant network.