I don't think the requirements have changed - for LAN play, there needs to be a max ping of 30ms. If you're in the same street as someone and using the same ISP, this should be possible. It certainly doesn't warm to connecting to people outside of your local area. I tried it with someone about 200 miles away and although we got our ping down to about 31ms, it was still stopping the connection (we were using Leaf BTW, another tunnelling software package). I could create a game and he could see the game available on the LAN - it was when he went to join we had the problems.
I think there's been talk in the past about bypassing this and because it's encrypted packets there's no way to intercept and change the value.
If anyone has an update which is different, I'd love to hear it