AR2C2: Actively replicated controllers for SDN resilient control plane

Controller Backup and Replication for Reliable Multi-domain SDN

“…In order to solve these problems, an active replication strategy is performed in the Ryu controller by Eros et al [14] to guarantee uniformity among the distributed controllers though the OpenReplica service. Naga Katta et al [15] introduced Ravana, a fault-tolerant SDN controller platform that processed the control messages.…”

“…(13) represents the probability of more than k' controllers fail concurrently. (14) means the probability of controllers concurrently fail is less than a certain value.…”

“…As for the controller deployment problem [7][8][9][10][11][12], most researches focused on the primary controller deployment, and there have been few studies on the deployment of backup controllers in multi-domain SDN. For controller replication [13][14][15][16], most existing methods are based on the communication between controllers, which might lead to inconsistency between controllers. Some approaches [17][18] used data store to avoid interaction between controllers for information exchange between working controllers, but these methods did not mention the detailed design of data store and the concrete steps of failure recovery based on the data store.…”

“…In UpdateSpeed() function of our algorithm, we generate |C|-bit integer as speed, and each bit ranges between -(| | -1) . Besides, if the amount of backup controllers showed by the new position is less than the result calculated by function (14), then we need to generate the speed and compute the new position again. Table 4 presents the pseudo code of the algorithm to calculate the location of the backup controller.…”

Analysis of monitoring and multipath support on top of OpenFlow specification

“…There are many ongoing research efforts on distributing such controller using peer-to-peer and hierarchical alternatives to ensure it is fault tolerant and highly available. [6][7][8][9][10][11] Given the stiffening of traditional networking solutions, in which the network elements were shipped (exclusively) with embedded control plane solutions developed by their own manufacturers, incompatibilities abound among devices from different vendors and even from the same vendor. In general, network operators prefer to deploy single-manufacturer solutions to minimize such incompatibility problems.…”