I have a similar issue with my DSL router. I'm given to understand from the router manufacturer and AT&T (cursed be their names) that the router is set up in the firmware so that the NAT loopback is disabled and you can't get to your own public IP address (i.e. you can't do things like ping your own fixed IP address). Basically this is to make it difficult for you, and to keep you from doing just what you are trying to do, set up a server at home.
Go to your nearest BarStucks (or Query-nos, etc.), order their cheapest item and user their internet connection to try your streaming service connection. I've got both Broadcam and Broadwave setup, but neither can test the internet connection from within the home network; yet both work just fine.
One other issue you will face is the upload speed limitations of your ISP. I have the DSL Ultra (~750Mbps) and I've had several service calls over to make sure I get the maximum on my connection speeds. I can send multiple audio streams all day long with no problems. The video streaming is another matter. If I buffer 30 seconds of video and play the stream, I can go for about 3.75 minutes before the buffer is exhausted and I have to wait for it to refill. I'm not really sure why this is as I work with our church to do a streaming service (using a Tricaster Pro system from NewTek) over the same type of internet connection and we can stream a signal for well over an hour without buffering problems (if you can believe our parishioners) . It is possible my server simply can't pump out the data fast enough, though I would doubt that as I have plenty of horse power for all my other tasks.
I hope this helps you (even though it doesn't contain a good solution).