Let's start with your ISP... AT&T are known for shaping p2p connections...
Router Blocking Limewire! no connection. help please!! Firewall/Proxy Settngs http://www.gnutellaforums.com/showth...379#post202379
If you could provide the make and model number for your router, I could see if it has a Nat Firewall....Just have a look underneath it, the info should be there...
Also check what version of limewire and Java you are using...
