Google describes its OpenFlow network

Benefits, challenges for OpenFlow
Google is still rolling out new features and procedures it wants to use on the OpenFlow network. Once they are running it will begin to quantify specific cost savings it already anticipates.

“We are clearly ahead in total cost of ownership and amortizing the development of [the switches],” Holzle said. Network “utilization improvements are clear, we are already at the same or better guarantees of service and once the network is fully implemented we expect we can operate and the same or higher levels with less effort,” he said.

In particular, OpenFlow promises to significantly reduce the time administrators currently spend configuring specialized systems, rolling out new network features and responding to outages. “Instead of updating hundreds of systems with thin memory and a little CPU, you update a few powerful control servers with tons of memory,” said Holzle.

“I am highly confident we will see substantial reductions in unit cost per month at given service levels, and we are already seeing signs of improvements better than any other technology change we might expect,” he said.

At this stage the OpenFlow network is robust and secure, but challenges are still ahead. It is particularly difficult to determine how to coordinate redundant OpenFlow controllers, Holzle said.

In addition, the standard is still in an early stage. The current spec doesn’t take advantage of features embedded in the ASICs in today’s routers and switches, according to engineers working on the next version of the standard.

In terms of the standard’s robustness, “I was willing to have more outages than we did,” Holzle said. In addition, “there’s no log-in to the box anymore, and intrinsically that makes you net more secure,” he said.

Google is acknowledged as running what is currently the world’s largest production OpenFlow network. But the technology is also at use in other business networks.

In a separate talk, an NEC executive said Genesis Hosting Solutions saw a 60 percent reduction in the number of global IP addresses it needed to support by moving to OpenFlow. Nippon Express Corp. has reduced rack space requirements, power needs and downtime by 70 percent or more with an OpenFlow network, he added.

Nearly 900 people attended the OpenFlow event including many executives from service providers, large switch and router makers and chip companies. The OpenFlow Foundation now has more than 65 members.