10G Ethernet vendor Force10 Networks is changing its core switch operating system to FreeBSD, an open source platform - continuing a major trend in the network industry.

The switch company has ported its Force10 Operating System (FTOS) from Wind River's VxWorks, a proprietary real-time operating system, to the open source FreeBSD, in an effort to make its data centre switches more stable and flexible.

The modular architecture of FreeBSD will make Force10's switch software easier to manage, especially for users running lots of network services or advanced protocols, the company said, adding that FreeBSD will let its E-series switches to operate like a Unix server, which runs separate applications and processes on top of a core operating system.

Network services will be easier to turn on and off this way, and new applications for the switch will be easier to develop, said Sachi Sambandan, vice president of engineering at Force10 Networks. Users will be able "to build networks that can expand as new applications are added while maintaining predictable performance," he said.

FreeBSD - also the base of Apple's Mac OSX kernel - is a Unix-based open source operating system similar, but unrelated to, Linux, and based on the Berkeley Software Distribution Unix variant.

Network vendors have used Linux and BSD-variant operating systems for years in appliances such as firewalls, small office or home router, and VPN gear. Lately, router vendors have begun to make open source a more central part of their systems. Cisco uses a Linux-based services blade on its Integrated Services Routers and 3Com recently released the Linux-based Open Services Networking blade for its routers.

While 3Com and Cisco run their core operating systems on proprietary code, others companies put open source in the core of their network gear. Extreme Networks' XOS operating system for its BlackDiamond, Summit and Alpine switches is based on a modified version of Linux. Vyatta takes this a step further with its Open Flexible Router, a free, Linux-based router/firewall software product based on the open-source eXtensible Open Router Project stack.

Force10 says FreeBSD will add another layer of redundancy and stability on top of its three-tier processor architecture, which uses separate chips to run switching, routing and management tasks, as opposed to combining these processes onto a single chip - and a single point of failure.

Open-source is now set to take off in networking, as it has in servers, said Robert Whiteley, senior analyst with Forrester Research. "When did open source systems like Linux take off?" he asks. "When a couple of well-know companies, like IBM and HP, forged relationships with Red Hat and other open source companies."

Force10 has been filling out its line with edge switches and security devices to compete with Cisco