Backup group multiplexing: an integrated restoration strategy for IP over WDM optical networks

This paper proposes a novel restoration strategy, called Backup Group Multiplexing, for fast restoration in IP over optical networks. It groups optical nodes by connecting them using switched multi-fiber 10-Gigabit Ethernet rings. It uses MPLS as the base technology to implement an integrated two-layer path-restoration scheme. It solves the problem of "failure propagation" by coordinating the backup path selection. It also takes the advantage of the label stacking capability of MPLS to groom IP flows to minimize the number of backup lightpaths. MPLS signaling protocols are applied across the IP layer and the optical layer in a coordinated manner. Our integrated scheme overcomes the shortcomings of uncoordinated protocols such as fail-over racing and double booking of backup bandwidth. The proposed solution is bandwidth efficient and cost effective.