While the open source community works on developing affordable substitutes for Cisco routers, Cisco itself is using Linux to power its Application and Content Networking System (ACNS), a caching and content delivery product for enterprise companies.
ACNS allows an IT staff to manage the flow of complex applications, audio and video over Cisco devices on a large network, with customers including Reuters, Siemens Medical Solutions and the U.S. Department of Veterans Affairs.
"ACNS has been based on a Cisco-modified version of Linux since its initial release," said Cisco spokesman Charles Sommerhauser. "There were earlier generations of related products that also ran on this OS. We use Linux on some of our products in order to integrate Linux-based applications."
The majority of Cisco's networking products run on its proprietary Internet Operating System (IOS) software. Open source efforts to develop affordable substitutes for Cisco routers include the Linux Router project (discontinued in 2002), FREESCO and now the Extensible Open Router Platform (XORP), which will issue its 1.0 release in May or June.
The use of Linux in ACNS cropped up in February, when we noted the presence of of Linux on the web site of the court hearing SCO's lawsuit against AutoZone. Further investigation found that Linux was being detected in the ACNS system serving as a front end for the court system's Case Management/Electronic Case Filing (CM/ECF) system, which runs on a Solaris x86 server.
Last year open source enthusiasts stumbled across Linux in the firmware for Cisco's Linksys WRT54, a popular wireless router for small business and residential networks using cable modems or DSL. At the time, Cisco was not releasing the source code for the Linksys firmware, a stipulation of the GNU Public License.
Lawyers for the Free Software Foundation pursued the matter with Cisco's lawyers, prompting complaints that GPL concerns would have a chilling effect on adoption of Linux in the enterprise. The disputed firmware code is now available on the Linksys web site.
Sommerhauser noted that Cisco is a founding member of the OSDL's Carrier Grade Linux Working Group. In December, Cisco executives told analysts of larger plans for the use of Linux, especially for some IP voice and messaging applications now running on Windows-based platforms.