Originally posted by OhVeec
Thanks for the responds, both of you. And I'm on Moderate, I used to be on open. But when I'm sitting in lobby, no one ever joins.
I have the same problem

Try this:
1. Turn off PS3
2. Reset your router/modem
3. Wait about 10 seconds
4. Turn on PS3
5. Your NAT should change from Moderate to Open.
I always do that and it works. But if you still can't find a lobby quit BO2, sign out of your PSN account, sign into another PSN account, then sign back into your hosting account. Do this a couple of times and it should work.