Oracle notched yet another acquisition Monday, announcing an agreement to purchase Xsigo Systems, a San Jose, Calif.-based, supplier of software-defined networking (SDN) technology. The terms of the deal, which is expected to close in the fourth quarter, were not disclosed.

Companies are embracing virtualization to support rapid, agile deployment at low cost. But virtualized servers introduce complexity with their many connections to external network and storage resources. Xsigo uses its Data Center Fabric architecture to converge network and storage traffic off host servers into Xsigo switching hardware, separating Ethernet traffic from SAN or Fibre Channel storage and boosting I/O performance. The combination of software and hardware provides what Xsigo describes as a "wire-once infrastructure" for virtualized deployment that minimizes the need for switches, cards, cables, and related administrative work.

"The proliferation of virtualized servers in the last few years has made the virtualization of the supporting network connections essential," said John Fowler, Oracle executive VP of systems, in a statement. "With Xsigo, customers can reduce the complexity and simplify management of their clouds by delivering compute, storage, and network resources that can be dynamically reallocated on-demand."

[ Want more on Oracle's last cloud move? Read Oracle Exalogic 2.0 Focuses On Elastic Cloud, Automation. ]

The virtualization market is consolidating, with category leader VMware announcing a $1.26 billion deal to acquire Nicira on July 24, just weeks after acquiring DynamicOps.

Xsigo has more than 300 customers, including British Telecom, eBay, Softbank, and Verizon. In a letter to Xsigo customers and partners, Fowler said the company will complement Oracle's software, server, storage, and network product portfolio and will round out the company's virtualization capabilities for cloud environments. Just last week, Oracle introduced Exalogic Elastic Cloud Software 2.0, an upgrade to the vendor's private-cloud application deployment appliance. That new software includes server-level virtualization capabilities that will make it easier to spin up and spin down capacity, according to Oracle.

The deal for Xsigo marks Oracle's fifth acquisition in the last three months. Three of those deals--Vitrue, Collective Intellect, and Involver--are in the social networking arena, while the Skire purchase brings Oracle cloud-based project portfolio management capabilities.

Expertise, automation, and silo busting are all required, say early adopters of private clouds. Also in the new, all-digital Private Clouds: Vision Vs. Reality issue of InformationWeek: How to choose between OpenStack and CloudStack for your private cloud. (Free with registration.)