The next time Bill Gates sends an e-mail through Microsoft's shiny new Wireless LAN it will be passed through a behind-the-scenes Linux-based network appliance.

Earlier this year Microsoft and Aruba Networks jointly announced the two companies will work to replace Microsoft's existing Cisco wireless network with Aruba's centrally-managed infrastructure, which eliminates the need for individual changes on the access points.

Aruba Networks was selected to provide the networking equipment for what is considered to be one of the world's largest next-generation wireless LANs, serving more than 25,000 simultaneous users a day in some 60 countries. According to an Aruba press statement, Microsoft's new WLAN will be deployed in 277 buildings covering more than 17 million square feet using Aruba mobility controllers, mobility software and some 5000 wireless access points.

What the press statement didn't mention is that Aruba mobility controllers run the Linux operating system which Microsoft has aggressively targeted as being inferior to Windows as part of its "Get the Facts" marketing campaign.

Mark Robards, Aruba Network's Asia-Pacific vice president, said the company's mobility controller switches provide integrated security, including a firewall, VPN, and hardware encryption, and they are "all Linux-based".

Robards said the network rollout with Microsoft is going well and is likely to take two years to complete and will contain as many as 7000 access points. Indeed, Aruba is recruiting Linux developers to work on its mobility controller software. In an advertisement on the company's Web site, Aruba is seeking a senior Linux software engineer with "expert knowledge of Linux and extensive Linux kernel experience".

Sunjeev Pandey, senior director of Microsoft IT, said the company is "pleased to be partnering with Aruba in the upgrade of Microsoft's next-generation wireless LAN".

"This partnership will allow Microsoft to leverage a cutting-edge wireless and mobility platform that provides us the scalability, performance and security that our environment demands," Pandey said.

Pandey's appraisal of Aruba's technology is in stark contrast to Microsoft's "Get the Facts" rhetoric which places Windows as a more secure, and higher-performing choice over Linux.