Oracle said Monday that it would buy network virtualization vendor Xsigo Systems. Xsigo is privately held, and Oracle did not specify the terms of the deal. Coming quickly on the heels of VMware's purchase of Nicira, the details of software-defined data center networks are falling into place. Oracle was the last large provider of data center gear without its own networking technology. Now, all of the major players in the data center own their own switching products, their own network virtualization technology, or both.

To quickly recap the major data center players, HP has long had its own line of ProCurve networking products. The line was largely intended for campus rather than data center working until the company acquired 3Com in late 2009.