"Google announced this week that it has overhauled its internal
networking infrastructure to reduce costs and increase efficiency.
To do this, Google is using a software-defined, open source
networking system called OpenFlow. The OpenFlow protocol allows
network packets to be routed by software running on routers. By
separating packet switching from network management, Google has
better and easier control over their network.
"From the OpenFlow website: OpenFlow enables networks to evolve,
by giving a remote controller the power to modify the behavior of
network devices, through a well-defined "forwarding instruction
set". The growing OpenFlow ecosystem now includes routers,
switches, virtual switches, and access points from a range of