Yesterday, Cisco announced its intent to acquire Stockholm-based SDN developer Tail-f Systems for $175 million in cash and incentives.

This move is just the latest in Cisco's aggressive movement into the SDN space.

Tail-f has a few big-name customers like AT&T and Deutsche Telekom.

Upon completion of the acquisition, Tail-f employees will join Cisco’s Cloud and Virtualization Group led by Gee Rittenhouse, vice president and general manager. 

- Cisco press release

According to Cisco, Tail-f’s products help service providers and enterprise IT organizations easily and cost-effectively implement applications, network services and solutions across networking devices.

There have been many acquisitions in the SDN space of late. I think we'll see that this is just the beginning.