Dynamic service-level-agreement aware shared-path protection in WDM mesh networks

Abstract

The notion of service level agreements (SLA) has been proposed to capture qualitatively and quantitatively defined performance contracts between service providers and their customers. How to provision satisfiable connections for customers according to their SLA parameters to avoid penalty as well as minimizing cost is one of the main concerns for a service provider. Connection reliability and restoration time are two important SLA parameters for a customer, and should be carefully considered in survivable wavelength-division-multiplexing (WDM) networks. A sound scheme should guarantee customers' reliability and reduce restoration time while benefiting a service provider in resource efficiency. Under the SLA constraints and the assumption of single link failure, we first investigate a partial link-disjoint protection (PLDP) and analyze its availability and average restoration time. We then propose a dynamic constraint shared path protection (DCSP) algorithm in WDM mesh networks. Based on the basic ideas of the K-shortest path algorithm and PLDP, DCSP can provide differentiated services for customers according to their SLA parameters while being favorable for reducing average restoration time and optimizing resource utilization. Simulation results show that DCSP can efficiently guarantee the specific SLA requirements of customers with a slight increase in the blocking probability while still achieving spare resource sharing and restoration time optimizations. © 2006 Elsevier Ltd. All rights reserved.