Follow the configuration and playback steps for RTSP streaming, and use an RTSP URL in Blackberry.
Mobile RTSP device can be difficult to reach. UDP ports are frequently a problem. And BB likes to have TCP port 554 open, the default RTSP port, otherwise you have to use port 1935 in the RTSP URL. For all of that, and other suggestions and ways to test the device, take a look at this article: