Dual stage hybrid restoration protocol for optical networks

To support the highly demanding quality of service (QoS) requirements of current and future communication networking services, network devices are required to support high-speed data transfer and also be very reliable. To ensure uninterrupted services, the restoration time in case of fiber cut or node failure has to be extremely low as disruption in high-speed networks causes considerable loss even if it is an extremely small duration. Restoration strategies like line restoration and path restoration alone have a mixture of advantages and disadvantages. To address this problem, we propose a dual-stage hybrid restoration protocol (DHRP) for achieving enhanced survivability in optical networks. In the DHRP topology, the moment that the event of link failure is detected, the line and path restoration procedures are initiated. The DHRP algorithm first conducts line restoration to immediately to restore the problem link. Then as soon as the path restoration topology is prepared it will be activated to bring the overall network traffic balance back to it optimal status. The drawback of the DHRP topology is the amount of backup capacity that is required to enable rapid line restoration. Although by implementing differentiated services combined with the DHRP restoration topology it is expected that the amounts of backup capacity can be significantly reduced.