Can SDN Make Optical More Accessible?

Some technologies are just ahead of their time. They make a tiny splash and then wander off to the periphery, either to become a successful niche or an unsuccessful afterthought. I learned this firsthand one weekend not long ago when my car broke down and I saw the mechanic calculating the bill on a tablet.

But it wasn’t an iPad, or something new. It was ruggedized and running an ancient version of Windows, cobbled and modified to accept a stylus’ input. I wanted to ask the guy if he knew how far tablets had come, but I refrained because it was clear that what he had worked for him.

On the opposite end of the user spectrum from tablets lies the niche of optical networking. Running up to the Web boom, there was a lot of hullaballoo around enterprises laying fiber. Vendors and analysts alike commonly recommended laying what was known as “dark fiber” – if you were doing any sort of digging or cabling projects, the idea was to lay fiber optic cabling at the same time so that it would be there when needed. Alas, Ethernet over copper speeds kept going up, and ATM and SONET costs over fiber never came down far enough.

But optical by no means went away. Just as that ancient tablet worked for the mechanic, optical has become a mainstay for telecom providers and other industry segments requiring high-speed communications. There are way too many vendors in the space – both established networking companies and startups – to call it a failure. It just never had a big enterprise presence.

But just as tablets have now become more common in the enterprise (and elsewhere), is it possible that software-defined networking could provide an opening for optical networking?

Lee Doyle of Doyle Research penned a very interesting blog post at SearchSDN positing this exact occurrence. “Optical networks are critical for handling increased bandwidth demands, yet they can be inflexible, difficult to provision and challenging to manage. Over time, SDN will change that and bring programmability, centralized control, dynamic provisioning and support for multi-vendor environments to optical networks. While technology for SDN optical networks is not yet as advanced as SDN for the data center, it will ultimately have a significant impact on high-speed transport in the wide area network (WAN).”

Over at the Optical Fiber Conference (OFC) blog earlier this year, long-time optical advocate Casimer DeCusatis welcomed the johnny-come-latelys to the optical world. But seriously, the work to connect SDN and optical has already started. As Lightwave’s Stephen Hardy noted last summer, the Open Networking Foundation (ONF) has created a working group that is helping to define how SDN might apply to the optical layer. But at the same time, he noted, even without a standard in place, networking vendors have already started to come up with ways to make this happen.

Julie Chao echoed the same sentiment in her Enterprise Networking Planet report from 2014’s OFC. More recently, Craig Matsumoto on SDN Central admitted that “SDN for optical transport isn’t a new topic,” and then that many vendors are working on it.

But one of the challenges of networking has been taking advantage of faster bandwidth when necessary. SDN helps admins route data over specific Ethernet network links for higher performance of prioritized applications; if SDN goes to optical, that same programmability could also apply to optical networks.

But as Alcatel-Lucent executive Basil Alwan, president of IP routing and transport, acknowledges in Matsumoto’s article, the challenge is “tricky” because of “the need to cross-manage IP and optical and to change both dynamically. You have to have a vision for managing routers and optical so you can get the efficiencies out of both layers,” he said. The ultimate solution will incorporate technology, not surprisingly, from Nuage Networks, its SDN-focused subsidiary.

In fact, the technological and management challenges will not be overcome easily. Alwan has been working on the problem for the last five years, adding that “It’s not going to happen in a day. It’s going to take some work.”

That’s okay. Optical networking has proven it has staying power, and a little more time won’t matter in the long run.


Copyright © 2014 IDG Communications, Inc.