A new protection model to provide availability-guaranteed service for reliable optical WDM networks

Reliability is a crucial concern in high-speed optical networks. A service-level agreement (SLA), which mandates high service availability even in face of network failures, must be met in provisioning reliable connection. In this study, we investigate a generalized connection-provisioning and protection model to provide availability-guaranteed services in a wavelength-division multiplexing (WDM) optical mesh network. A novel link-state model is proposed to represent physical-layer availability and resource status for an optical link. This information can be used by a standard link-state routing protocol to efficiently provide reliable connections. In our proposed link-state-modeling mechanism, current network resource information and the physical components' failure characteristics are aggregated to form a comprehensive dynamic link-state parameter, called link and resource availability (LRA). Based on such a dynamic link-state parameter, we also propose an algorithm for availability-guaranteed connection provisioning. A new generalized protection model is developed through our dynamic LRA-based provisioning. The dynamic LRA-based connection-provisioning algorithm efficiently provides SLA-guaranteed services while significantly improving connection reliability, better utilizing network resources, and achieving fast failure recovery.