The domain oneplay.tv is pointing to a website using port 80, so you will likely need to use a DNS host entry such as "video.oneplay.tv" or use port 1935 for video connections. This may require some additional routing configuration to enable a port forwarding to the Wowza server as oneplay.tv does not currently respond on port 1935. As Jason mentioned, it could also be that Wowza Streaming Engine is not currently running.
When using sub-directories, you may also need to add "_definst_" after the Application name. As follows: