Amid chatter that Ciena could be an acquisition target, the company became an acquirer today, saying it's buying Cyan Inc. for roughly $335 million net. (That's $400 million in cash and stock, minus Cyan's cash holdings.)

The deal, expected to close by Ciena's fiscal year-end in October, values Cyan at about $4.75 per share, a premium of about 30 percent above Cyan's Friday closing price of $3.65.

Naturally, Cyan's shares shot up Monday morning. At press time, they had risen $1.03 (28%) to $4.68.

Ciena's shares were up as well, climbing 27 cents (1%) to $21.56 at press time.

Lately, the talk has been that Ciena could be on the other end of an acquisition, with Ericsson as the buyer. No actual rumor to that effect has started yet, but the assumption is that Ericsson might feel pressured by Nokia’s pending acquisition of Alcatel-Lucent. A pickup of Ciena would give Ericsson, which is using Ciena as its optical-networking partner, a comprehensive span of telecom gear to better rival Nokia’s.

Cyan is one of those companies that can claim to have started thinking about SDN before "SDN" became an industry buzzword. It was founded in 2007 as Cyan Optics, and while it aimed for combined control of the packet and optical networks, it still had a hardware focus typical of the times.

By 2011, as SDN emerged, Cyan de-emphasized the optics, even dropping "Optics" from its name. The company still sells packet-optical gear but concentrates on the management plane with its Blue Planet. Of particular note was Cyan's ability to manage other vendors' equipment, within certain boundaries — an idea now made common by SDN. Cyan has expanded its Blue Planet software to work with even some Cisco and Juniper equipment.