Miscellaneous

In addition to the soft switches and controllers, there are many other open source projects around OpenFlow and SDN. In this section, we provide pointers to some important open source projects.

FlowVisor

A SDN can have some level of logical decentralization, with multiple logical controllers. An interesting type of proxy controller, called FlowVisor, can be utilized to add a level of network virtualization to OpenFlow networks and allow multiple controllers to simultaneously control overlapping sets of physical switches. Initially developed to allow experimental research to be conducted on deployed networks alongside production traffic, it also facilitates and demonstrates the ease of deploying new services in SDN environments. FlowVisor is a special purpose OpenFlow controller that acts as a transparent proxy between OpenFlow switches and multiple OpenFlow controllers, as shown in the following figure:

FlowVisor as a network slicer

FlowVisor creates rich slices of network resources...