MRV's latest gear does SDN. You can tell. It's got ports literally labeled "SDN."

Laugh if you will, but there really is software-defined networking (SDN) behind it. The port — a feature on the Optipacket (OP-X, for short) packet-optical switch that MRV introduced this month — lets an external controller talk directly to data-plane processors in MRV's box, bypassing the box's own control plane.

They didn't have to call the port "SDN," but the name reflects a pragmatic bit of strategy. "We're not going to be the SDN company," Scott Wilkinson, MRV's senior director of technical marketing, said at the recent Big Telecom Event in Chicago. "We have all the bricks. We can build an SDN house. We're just not sure anybody wants to buy it yet."

To that end, the OP-X is being marketed as just a switch, not an SDN switch, although SDN functions can be run on top of it. In that sense, it's one of an increasing range of products targeted at sprinkling incremental bits of SDN or network functions virtualization (NFV) onto a familiar network architecture, for customers that like the ideas but don't want to make radical changes.

MRV might have another reason not to pursue end-to-end SDN. The company makes packet-optical transport gear that competes with products from Alcatel-Lucent, Ciena, Cyan, and Fujitsu — and many others; it's quite a fragmented market, and several of those names are pursuing broad SDN deployments.

MRV would have a hard time competing on that front, especially considering it's far from a market leader in optical networking. (AlcaLu or Huawei usually takes that crown, rarely, if ever, exceeding 25 percent market share.) MRV is also rebounding from having pared down its business to optical networking and Carrier Ethernet, a strategy that launched in 2012.

So unlike, say, Cisco, which supplies entire networks to some customers and would certainly love to do the same for SDN, MRV can content itself continuing to be a piece of a larger picture. Specifically, the company doesn't plan to get into orchestration or offer an SDN controller yet, Wilkinson says.

Having said that, the OP-X has enough processing to act as an SDN controller for devices further toward the network edge — the network interface devices (NIDs) that MRV also sells. Those NIDs could also run virtualized network functions, putting the OP-X in the role of controlling network functions virtualization (NFV) that's distributed at the network edge — an architecture also pitched by RAD Data.

The OP-X aims for compactness and low power consumption. It's a box 10 rack units tall, able to hold four cards with 40 10-Gb/s Ethernet ports apiece; those cards also house the processors that can interact with the "SDN" ports. The target markets are aggregation and metro core networks, but not the heavy-duty network core; the OP-X isn't meant to challenge something like Juniper's PTX, for instance.

(Photo by Zeev Draer of MRV.)