An attempt at Floodlight Development.

This page documents the (attempted) process of developing a version of Floodlight with FlowVisor-like slicing capabilities.

This is an on-going process - therefore this page will be updated frequently.

Overview.

Slicing is the SDN (in our case referring to OpenFlow) term for network virtualization. Specifically, A slice is a SDN controller and the network resources allocated to it by a hypervisor-like entity such as FlowVisor. With proper resource isolation and allocation, multiple controllers can coexist on a single physical network.

In the usual case, FlowVisor behaves as a proxy, intercepting and modifying the OpenFlow control messages between the switches and the multiple controllers so that each slice only sees a subset of the network.

Floodlight is a modularized OpenFlow controller, in that its functional components can be split into two major parts:

1. The core event dispatcher, and
2. The various event handlers.

The event handlers (Floodlight modules) are what define the behavior of swicthes (hub, learning switch, router, etc.). A more in-depth discussion of these components can be found ​here.

The key point here is that Floodlight's modular structure allows for multiple different handlers to coexist, with various (groups of) modules imposing different capabilities on the switches. If these modules controlled different groups of switches e.g. had their own bit of resource, each <module:resource> set can be viewed as a slice. Floodlight does not currently have this capability, so the objective of the process described here is to try to realize this feature.

Approach.

Development is done on two VMs, one hosting Flowvisor and Floodlight source, and the other, Mininet for testing our code.