Port Forwarding help required (I think)

HI & Happy New Year to all

I want to stream a webcam to my web site using http://www.camstreams.com I have downloaded their encoder and have it up and running on my pc OK. The problem is though that the Camstreams servers cannot see my PC to pick up the signal.

From the Camstreams website help pages the problem seems to be that I have an external IP address of 80.5.xxx.xxx which I understand to be a private address, but my 'Default Gateway' IP address is '192.168.x.x' . The answer apparently is to use Port Forwarding, but I can't find how to do that for my BB setup.

I connect to the internet via an NTL cable modem the only markings on it seem to be "NTL home: 100" made in China, and this does not figure in the camstream extensive list of routers and how to set them up on the page that they direct you to http://www.portforward.com/english/applications/port_forwarding/camstr/camstrindex.htm. I am assuming that the cable modem I have is also a router.

There is some more info on the Camstreams configuration requirements here http://www.camstreams.com/broadcaster-network.asp I have a feeling that the solution is probably something fairly easy but I don't understand enough how these things work to get any further. That's where you guys come in (I hope).

I have tried disabling the firewall and that makes no difference.

I am running Windows XP Home Sp 2. I guess there is probably more info you need & I will be happy to provide, you only have to ask.

That's where you guys come in (I hope).

Thanks for your help.

Regards

Peter
UK