Software defined optical network controller deployment method based on multi path survivability protection

A software defined optical network controller deployment method based on multi-path survivability protection, characterized by comprising the following steps:

• step 1:
• calculating the length W of the longest control link under a single controller according to the probability P specified by a user to ensure the survivability of network topology;
• step 2:
• calculating the shortest path Lij between switches V by using the Floyd algorithm, taking Lij as the weight of connection between Vi and Vj, and converting SDON network topology to a complete bipartite graph;
• and deleting any link with Lij>W, ensuring that the length of each feasible path is less than W, and forming a new bipartite graph G;
• step 3:
• reconverting G to network topology, distributing switches with feasible paths to the same area, wherein the topology is usually divided into n areas, and a switch in the ith area is represented by φi, forming different areas into a set {φ1, φ2, . . . , φn}, and calculating a set {θi1, θi2, . . . , θin} of optimal minimal dominating sets in φi, wherein n represents the number of switches in the minimal dominating set;
• and the deployment position of the optimal minimal dominating set is the deployment scheme of a single controller, and a deployment scheme containing redundant controllers is obtained and represented by a set {C1, C2, . . . , Cn};
• step 4:
• reordering controllers in the set {C1, C2, . . . , Cn} from small to large based on the number of switches under respective control to obtain a new set {C′1, C′2, . . . , C′n}, and trying to delete the controller C′1;
• step 5:
• when C′1 is no longer used as a controller, representing isolated switches by a set {S1, S2, . . . , Sn};
• and finding k (k≥2) new control links for Si by using the Floyd algorithm, wherein the Floyd algorithm is used for finding the shortest path from Si to other nodes, and appropriate control links and the number thereof are selected so that the network fault probability meets the survivability requirement;
• step 6:
• judging whether Si can achieve the network survivability after being linked to a new controller by using the calculation formula of the network fault probability under multiple controllers;
• if all switches in the set {S1, S2, . . . , Sn} find satisfactory controllers and control links, the controller C′1 can be deleted, and the new controller is added to a set {Vpc1, Vpc2, . . . , Vpcn};
• otherwise, C′1 cannot be deleted, and C′1 is added to the set {Vpc1, Vpc2, . . . , Vpcn};
• step 7:
• after operation of C′1, repeating steps 4, 5 and 6 until the operation of all controllers in the {C′1, C′2, . . . , C′n} is completed, and the set {Vpc1, Vpc2, . . . , Vpcn} is an SDON controller deployment scheme based on multi-path survivability protection;
• step 8:
• determining the deployment position of the control center Vcc based on coordinated signaling transmission time delay between the controllers.