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.
Source and full article at: Google Reveals its Open Source Networking | WebProNews.