Resiliency-aware hybrid design of controller-switch connectivity in a split-architecture system

摘要

A method and apparatus for optimizing the resilience of a network using a combination of in-band and out-of-band signaling is disclosed. The metric used in the embodiment's algorithm to determine resilience is the maximum number of protected neighbors. Nodes closer to the controller are assigned a higher weight than those further from the controller because if their connection to the network is interrupted, all their downstream nodes will be affected and disconnected. Therefore, when determining a path to the controller, switches with alternate paths to the controller are preferred. Dedicated connections using out-of-band signaling are assigned to convert unprotected nodes to protected nodes thus improving the resilience of the network.

主权项

1. A method implemented by a network topology design system to determine a controller routing tree for use within a split architecture network where control plane components are executed by a controller and the data plane components are executed by a plurality of switches, the method comprising the steps of:
calculating an initial controller routing tree using in-band connections for control traffic between each switch and the controller; calculating the resilience of the network having only in-band connections; establishing a parameter m, each of m representing a dedicated connection between a corresponding switch and the controller for out-of-band control traffic; and determining, using an approximation algorithm, the placement of each m dedicated connection between a switch and the controller so as to optimize the configuration of in-band and out-of-band connections for maximum resilience.