NICs Redundancy Technology In Embedded Real-time Operating System ARTs-OS

With the rapid increment of quantity and transmission speed of data in computer-network, the reliability of network becomes more and more important. Especially in financial institutions, government departments, military and other special applications, the reliability becomes the key factor determining network performance. In order to improve computer-system reliability and survivability, the network redundancy technology is invented.ARTs-OS is designed and implemented on the base of S3C2410 chip, it has basic functions including process/thread management, memory management, IPC management, interrupt and clock management. Through analyzing the network subsystem of ARTs-OS, the idea of implementing network redundancy in data link layer is suggested. That is to say, hot switch of network card is implemented by network driver for network redundancy. Network driver is divided into three sections including data transmission of network card, switch of network card and error checking in order to achieve the function of network redundancy. Network subsystem is loaded into kernel as process outside kernel. Based on this architecture, I/O technology outside kernel basing on hard interrupt outside kernel of ARTs-OS's driver device is discussing. Aiming at jam of data pack resulting from the difference between network dispatcher speed and CPU operation speed, cache in network driver is discussed. In accord to the principle of network hot switch, binding of TCP/IP and ARP protocol are analyzed thoroughly in order for better explain of the whole hot switch process and then error checking is achieved.Through test of the performance, such as switching time, robust, losing of package, and adopting redundancy configuration in embedded system, not only the speed of data transmission is very high and ability of anti-jamming is wonderful, but also the stability and reliability are improved.