Research On Cross-layer Survivability Strategy For Software Defined Optical Network

With the increasing of user bandwidth demand and the application of advanced optical modulation techniques, the transmission capacity of optical network has achieved geometric growth. Therefore, optical networks need to be more intelligent control capabilities and better survivability. The software defined networking(SDN) technology has been applied to the control of large-capacity optical network, it can satisfy the requirement of intelligent control capabilities, but the reliable operation of the control plane is totally dependent on the few distal SDN controllers, so it exacerbated the problem of control plane survivability. Meanwhile, the problem of data plane survivability still exists. The traditional design of survivability is often in single layer, and because their strategy do not cross-layer share, easily lead to duplicately allocate resources for protection, waste of resources, will cause cross-layer survivability strategy to conflict in severe cases. Therefore, on the basis of relevant research, this paper carried out a cross-layer survivability strategy on control plane and data plane for software defined optical networks(SDON), based on globally cross-layer centralized SDON network architecture.In order to effectively improve the survivability on the control plane, the Survivable Strategy of SDON Control Plane Based on Minimum Point Covering is proposed, composed by controllers deployment algorithm using minimum point covering and survivability against control channel failure based on cross-layer Information model. Combined with the constraint of centralized control, the algorithm based on the minimum point covering, establishes reliable hierarchical control model,and sets control priority to controllers. Meanwhile, the model based on cross-layer information designs survivability redundancy for routing and allocates resource for the control channel. Simulation results show that the proposed strategy can satisfy the request on control delays, and lower the failure probability in the control plane by 30%, thus promoting the network survivability under critical environment.In order to ensure reliable data transmission on the data plane, and minimize resource consumption simultaneously, the Survivable Strategy of SDON Data Plane Based on Cross-Layer Synergetic Optimization Model is presented. First, Cross-layer Synergetic Optimization Model(CSOM) is established, through the re-division of the data plane hierarchy to achieve the refinement of network resources. Secondly, globally and fine-grained mathematical modeling for cross-layer network resources is established based on CSOM, thus forming a four-layer "network status information database" in the SDN controller. Thirdly, working and protection routes are cross-layer calculationed for service requests, at the same time the protection resources is shared and compressed. Finally, the simulation shows that the strategy can ensure service reliability and effectively improve network resource utilization.