IT shops share OpenFlow, SDN best practices

Start small, go slow and reap the benefits, users say

NEW YORK — 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.

Unlike Marist, which is allied with IBM, NEC and ADVA, Bloomberg is investing in “the little guys,” Boyes said.

“It’s something new, you both have skin in the game and you can affect the road map,” he said. “Control your own destiny. We take on more risk in trying to roll it ourselves. You have to leverage as much code as possible from the community.”

For those embarking on SDNs, Cannistra recommends picking a controller first of all. Marist started with the open source Floodlight code but then switched to NEC for production use.

“In production, you’re going to have to use some proprietary features,” he said. “Floodlight…was not production ready. Spin it up, get some production traffic on that and then have a path to open standards.”

He said he is looking forward to the OpenDaylight open source controller being built by several vendors and other community members, including partner IBM.

“I have high hopes for OpenDaylight, I’m one of the optimists for it,” Cannistra said. “It’s standards we can all build on going forward.”

The fact that open source SDN code doesn’t have a support infrastructure around it doesn’t scare Cannistra away either.

“Companies built support models around Linux,” he said. “Why couldn’t they do the same with Floodlight or OpenDaylight?”

One of the SDN wrinkles still to be worked out is how it will affect the organizational structure of IT – the siloed server, storage, networking and application departments, the speakers said. Bloomberg and Marist are tackling it their own ways.

“There’s a lot that has to happen,” Cannistra said. “We’re still going to have niche guys but also people with a large-scale view. Those are going to be your powerhouse guys and girls in the enterprise.”

It will be disruptive within Bloomberg, Boyes acknowledges.

“We’re trying to address it at an organizational level by rocking the boat,” he said. “We’re just going to have to figure it out. We’ve put together a cloud team to straddle both worlds, jump start the rest of the organization. That will help us with time to market.”

Despite the uncertainty organizationally, Marist, for one, is all in.

“This is game changing,” Cannistra said. “We need to go full steam ahead.”

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