Tail-f Systems is a small company that's made a big name for itself in network configuration. Now it's making itself part of Cisco.

Cisco announced this morning its intention to acquire privately held, Stockholm-based Tail-f for $175 million cash. The deal is expected to close by Cisco's fiscal year-end in July, at which point Tail-f would become part of Cisco's Cloud and Virtualization Group led by Vice President Gee Rittenhouse.

Tail-f's NCS platform uses the Netconf protocol to configure a network, and it's gained some important carrier attention along the way since being introduced in 2011. Tail-f has been deployed in Deutsche Telekom's Terastream next-generation network, and it was selected as an AT&T supplier under that carrier's Domain 2.0 program.

In one sense, the deal could cause some hand-wringing over Cisco owning what's become a promising slice of the software-defined networking (SDN) ecosystem.

On the other hand, it could be a sign that Cisco is serious about keeping its architecture open. Much of the industry has eyed Cisco's Application-Centric Infrastructure (ACI) with suspicion, especially when it comes to the OpFlex protocol for communicating policy details. Cisco has made OpFlex available through the IETF, but it's still a Cisco-originated protocol.

NCS, while not a declarative, policy-driven option like OpFlex, would let Cisco offer an option that's more definitively open. Netconf didn't originate with Cisco or Tail-f; the protocol's origins are tied to Juniper more than any other vendor.

Cisco is pledging to continue supporting Tail-f's partners and customers after the acquisition closes, of course.

Tail-f and Cisco are both hanging out at the Big Telecom Event in Chicago this week, so we might have a chance to update the story soon.