No operating system is an island
At F5 Networks, our BIG-IP device for application delivery networking combines the functions of a dozen or more single-purpose network appliances. Web application acceleration, load balancing, low-level packet routing, content compression, client authentication, rate shaping, and IPv6 gateway services are just a few of its services, and BIG-IP's capabilities are getting bigger as new ones are added.
|The BIG-IP device by F5 Networks uses an operating system and embedded database management system to stay afloat in a sea of real-time data.|
These applications' need for high performance, availability, and reliability--and F5 Networks' desire for scalability and extensibility, so the device's features can keep growing--led the company to design and build a specialized embedded operating system for the BIG-IP product family.
In this article, we describe why we enhanced BIG-IP with an embedded operating system and an embedded data management system, specifically what technical issues we were trying to avoid. This approach could be of use to embedded systems engineers developing networking, communications, or any other type of complex real-time application in which multiple processes read and update shared data in order to perform their work.
An operating system for BIG-IP
The Traffic Management Operating System (TMOS) is the operating system we built for BIG-IP. It's an embedded device platform that is highly optimized for delivering applications over the Internet and other IP networks, and gives the device a performance edge. BIG-IP's popularity has drawn attention to TMOS, and while nearly all the notice has been positive, our operating system has sometimes been mischaracterized as a Linux variant. In fact, BIG-IP does include a copy of Linux, which runs alongside TMOS and provides certain management tasks, such as the command line and Web graphical user interface.
However, the packets flowing through BIG-IP are not "touched" by Linux in any way. Every important system aspect is contained within TMOS and optimized for high-speed, high-volume traffic-management applications. TMOS has its own microkernel, the Traffic Management Microkernel (TMM).
BIG-IP's platform reimplements standard operating system features such as the scheduler and Secure Sockets Layer stack to achieve lower overhead and higher flexibility. It also adds new capabilities, such as iRules, a scripting language (based on Transaction Control Language) for real-time manipulation and modification of traffic, to enable users to achieve complex networking goals.