A 1,000-fps visual tracking system over a realtime network based on the standard Ethernet and UDP/IP technologies is presented. The system consists of a high-speed vision system, a host PC that executes motor-control tasks on an RTOS, and an easyto- construct configuration for real-time communication to deliver the high-speed visual feature information obtained by the vision system to the host PC. Rather than introducing OS-dependent technologies for realtime communication, we have developed a dedicated network processing unit that handles all of the UDP/IP and Ethernet processing instead of the host PC. The visual information packets are forwarded in priority to the other background traffic by off-the-shelf Gigabit Ethernet switches with the IEEE802.1Q/p QoS mechanism. Experimental results show that the end-to-end delay through three Ethernet switches is below 180 μs with 20-μs jitters even under a high network load.