Google Unveils Secret, Worldwide Networking Project

The project, which Google has dubbed its “G-Scale Network,” replaced all existing switches and routers with equipment that used the OpenFlow protocol. The protocol, which was initially conceived by a graduate student at Stanford University named Martin Casado, represents a new way to control network switches and routers that has come to be known as software defined networking, or SDN.
http://www.openflow.org/wp/learnmore/
http://en.wikipedia.org/wiki/OpenFlow
By separating the software that controls network traffic from the physical routers and switches, SDN should make networks more secure, more dependable and much easier to manage. Because SDN runs on commodity hardware, it could translate into siginficant savings for network operators. Perhaps most important, it opens up the network to the possibility of vast innovation.

For Google, software defined networking represented a better way of moving traffic between its global data centers. According to Holzle, things that were hard to do on processors embedded in a networking box become much easier when they separately designed and merely communicated to the hardware using OpenFlow. “You can use all the [computer] tools for software development and that makes it faster to develop software that is higher in quality,” he said.

One of the big advantages for Google is better traffic management—this new approach basically ensures that every lane on its global network of data highways is smoothly moving packets toward their destinations. “Soon we will be able to get very close to 100 percent utilization of our network,” Holzle said. This is a big increase from the industry expectation of thirty to forty percent utilization.
http://www.forbes.com/sites/eliseackerman/2012/04/18/google-unveils-sec…