I'm trying to use FaceTime for the first time, but when I put in my apple ID i get the message "Could not sign in. Please check your network connection and try again." I'm using an iMac [Lion] and a 1 year old airport extreme. I found this article [ http://support.apple.com/kb/HT4245 ] about opening ports, but I can't find any instructions on how to do that. 
Do you think this is the problem. How do I open the ports?
thanks
Do you think this is the problem. How do I open the ports?
thanks