Numerous tools have been developed for generating artificial traffic flows. These traffic generators are commonly used for emulating applications, measuring various network characteristics, or just generating traffic for performance tests. The performance of many applications, such as packet measurement tools, heavily depends on the packet rate of the network traffic under observation. The existing traffic generators are mostly user space implementations, which limits their performance, especially in high-speed networks such as Gigabit Ethernet. In this paper we present and evaluate KUTE, a UDP packet generator and receiver which runs entirely in the Linux kernel. We compare KUTE with a similar user space tool named RUDE/CRUDE and find that KUTE is able to send and receive much higher packet rates, produces more accurate interpacket gaps at the sender, and more accurately measures interarrival times at the receiver.