As Dan pointed out UI.start_timer works pretty good with UDP. Here's how I'd write it: require 'socket' serverSocket = UDPSocket.new serverSocket.bind("127.0.0.1", 3157) timer_id = UI.start_timer(0.1, true) { begin data = socket.recvfrom_nonblock(100) new_message = true rescue Errno;;EWOULDBLOCK new_message = false rescue Errno;;ECONNRESET new_message = false UI.stop_timer @timer_id break end if new_message == true UI.messagebox(data) end } The major different is the UI.start_timer in place of the "Thread" and "Loop" in your example. You'll also see that it uses .recvfrom_nonblock with some error catching instead of just .recvfrom. This is because sketchup will hang if nothing is sent to the socket. If you're sure that there will be a constant stream of data you might be able to get it to work with blocking.