RTMP and Red5, how does it work?

This is just a little question I have.

How do RTMP/RTMPT audio streams work with red5 and Flash 9?

I have been searching around the internet looking for how these transport protocols work, and though I've found little snippets, I haven't found definitive answers. The main aspect that I'm looking at is the interaction between a router/firewall, the external red5 server, and the inner Flash 9 client.

I've done packet traces on a working computer and also a non-working computer using wireshark. It doesn't appear to be blocked by the firewall or router which I know have a problem with RTP. What I have come up with so far is that, on the Flash 9 client, the NetConnection will communicate perfectly, the NetStream seems to initiate, but it won't send any audio packets. Is there something I'm missing in the client?

If anyone has any answers, please feel free to post. I will keep this updated with any progress I find.