Partial Spatial Protection for Differentiated Reliability in FSTR-Based Metro Ethernet Networks

Fast Spanning Tree Reconnection (FSTR) is a newly proposed restoration method by us to handle single link failures in Metro Ethernet networks. Compared with other methods existing in the literature, FSTR has the advantages of lower signalling overhead, faster recovery and lesser rerouted traffic. In this work, we propose to use partial spatial protection (PSP) mechanism to provision differentiated reliability (DiR) and, as a result, to decrease the blocking probability of traffic requests in FSTR- based Metro Ethernet networks. In PSP, a traffic request is protected using backup bandwidth against the failure of only a subset of the links on its route. We develop a mixed integer linear programming (MILP) model for PSP to minimize the bandwidth reserved by an incoming traffic request while satisfying the protection grade required by the traffic request. The numerical results demonstrate that the proposed solution can reduce the blocking probability of traffic requests by up to 83% in a 4×4 grid network, compared to that in full protection.