The UDP Test tool is a connection testing tool that is similar to iperf. This tool has been created partially due to limitations in iperf. This tool is designed to test downstream throughput and measures the speed of a connection by sending UDP traffic very quickly to a downstream client and measuring the packet loss and adjusting the send rate accordingly.
There are currently some issues with the UDP Test tool. Right now, it is not able to show similar rates as iperf (using tcp). UDP should be faster than TCP and so presumably the transmit rates of the tool should be higher. Because of this it seems that the UDP Test tool is not impacted significantly by interference. A good alternative is to use iperf with the -i and -t options.