Reliable Multi-Path Provisioning for High-Capacity Backbone Mesh Network

We investigate reliable multi-path provisioning of traffic in high-capacity backbone mesh networks, e.g., nextgeneration SONET/SDH networks supporting virtual concatenation (VCAT). VCAT enables a connection to be inversely multiplexed on to multiple paths, a feature that may lead to significantly improved performance over conventional single-path provisioning. Other mesh networks such as those employing optical wavelength-division multiplexing (WDM) and multi-protocol label switching (MPLS) can also benefit from this multi-path provisioning approach. We propose effective multi-path bandwidth as the metric to provision a connection while satisfying its reliability requirements (measured in terms of availability). We demonstrate that effective multi-path bandwidth provides more flexibility and lower blocking probability without the cost and the complexity associated with traditional protection schemes developed for optical WDM and MPLS networks. We also investigate the practical problem of provisioning effective multi-path bandwidth with cost constraints. We analyze the tractability of the problem and present a heuristic which results in significantly reduced number of blocked connections due to cost constraints. Index Terms virtual concatenation, multi-path provisioning, flexible provisioning, degraded service, effective multi-path bandwidth, multi-constrained paths.