When viewing a live video over the public Internet, several factors can affect your ability to view, or affect the quality of the video.
1) Check Your Desktop Player
Be sure you have the current version of Flash Player. You can download the latest here.
2) Check Your Bandwidth
You may not have enough bandwidth to view the video. That you think you have a high speed connection does not mean you do right now, as others in your home, building, or within your provider, may be using all of the network capacity. Try running at test using http://speedtest.net
3) iPhone/iPad/iTouch (iOS devices)
Streaming is high bandwidth. For best results, use WiFi. For 3G or 4G connections, be sure you have enough bandwidth available
Currently, viewing on Android is an industry issue because there are many versions of the OS and carriers have been slow to roll out updates. It may be best to download a third-party live video player that supports RTSP.
If the video is available to Roku viewers, try to reload the channel. In some cases, it may be necessary to power cycle to box if the target channel does not appear.
If possible, see if others are able to view with good results. If they can, then the problem is your computer of device.