NAT Loopback is when you stream video from your PC to livehamcams.com and you can not see your video on that page and everyone else outside your network can.

Please read the linked article on the website about NAT Loopback to fully understand 

My work around for this issues is to modify the host files, do not attempt this unless you fully understand host files and OS

The first thing you will need to do is sign up for a free Dynamic DNS 

Next, you will need to add this entry to your host files

(This would be your local IP of the computer that you have webcamxp running on) 192.168.x.x   (This entry would be the free DNS that you signed up for) yourcall.dynamic-dns.net

Mine would look like this 192.168.1.50  k3bm.dynamic-dns.net

That should work for you if your router does not support NAT Loopback

73's

K3BM

Resources: 

http://www.changeip.com/dns.php

http://www.howtogeek.com/howto/27350/beginner-geek-how-to-edit-your-hosts-file/