An Innovative Restoration Algorithm with Prioritized Preemption Enabled

This paper proposes an innovative prioritized restoration algorithm which enables carefully scheduled preemption (RAPPE). Firstly, it makes dedicate differentiation among network resources based on their roles in holding up services (working or backup) as well as the service levels they are carrying; secondly, it enables both higher level service preempting resources of lower and lower level service utilizing spare resources of higher; thirdly, it carefully schedules preempting rules. Simulation results show RAPPE satisfies various service requirements according to their priority levels and improves the network resource utilization sharply. Moreover, RAPPE also achieves wonderful performance in preemption perspective for it minimizes the preempted service level as well as the number of preempted services, both of which are important criteria in evaluating a preemption algorithm. Furthermore, to implement the RAPPE in existed networks, only a simple PathCost object needs to be installed on the existed routing module of edge nodes.