IT shops share OpenFlow, SDN best practices

Two users are putting OpenFlow and software-defined networks through their paces in projects of varied urgency.

Marist College is very bullish on OpenFlow as a way to interconnect data centers over optical fiber. The company is using OpenFlow controllers from NEC and IBM, and optical transport gear from ADVA.

Bloomberg, the business and financial market trading and media enterprise, is a bit more conservative in its implementation. The company is employing OpenFlow for monitoring and tapping, and network virtualization overlays for simplifying and scaling its data center fabric.

Both users spoke at the recent Interop conference and exhibition in New York.

Marist began researching OpenFlow and SDNs two or three years ago for monitoring servers, manipulating flows and moving VMs.

“How far can we take OpenFlow, and what can it do?” said Rob Cannistra, a computer science and IT professor at Marist. “We were a skeptic at first and now a true believer.”

Marist worked with the Floodlight open source OpenFlow controller but found that it needed a GUI. So the college created a GUI for Floodlight to add, delete and modify flows. It also developed a QoS module for the controller to prioritize flows.

The school also used the open source Ganglia tool for monitoring servers. Ganglia helps the school determine how to manipulate flows to move VMs when server resources require or accommodate it.

With these tools, Marist created a host-aware networking module within its data centers, Cannistra said. But the school now wanted to scale this host awareness among data centers, not just within.

Two weeks ago, Marist proved that it could use OpenFlow to spin up and tear down a wavelength between data centers to migrate VM workloads among them. The school tied sites together with optical connections through Internet2. It spun up connections to three different data centers using OpenFlow and SDNs.

The OpenFlow network was turned up in parallel with Marist’s traditional network, Cannistra said. A building or two was brought onto the OpenFlow network and then both networks were interconnected slowly and prudently.

“We have some individual data centers that are on the OpenFlow network, and we’re seeing how it scales,” Cannistra said. “We’re taking a very slow approach to it.”

Marist is still working with OpenFlow 1.0 code, working its way up to 1.3.

OpenFlow is the backbone of a purpose built network for traffic monitoring and tapping of financial application development at Bloomberg. The company didn’t want to clog up its production network with MAC learning conversations, says Truman Boyes, Bloomberg network architect for Research & Development.

Bloomberg is also looking at how an SDN overlay scales for onboarding and off boarding inter-cloud users. But the company is taking a very gradual, deliberate approach with its implementations.

“Most technologies work in small scale,” Boyes said. “Significant results with low impact is the place to start.

“But SDNs are absolutely consumable. You need to take an investment so you can get on that wagon and learn with everyone else. It’s like MPLS 10 years ago.”

Marist’s Cannistra agrees.

“Take baby steps,” he said. “Look at a use case you’re having difficulty attaining with a traditional network.”

“SDN is when protocols don’t cut it,” Boyes adds.