I got a small wireless network at home. I have had as many 4 people playing FTP and PS at the same time. So I don't believe you have anything to worry about.

The catch is, per FTP customer service, multiple computers from the same IP address will not be allowed to sit at the same Ring game tables or to register for any tournaments/S&G's with less than 45 people.

Anything above 45 people is open to multiple computers from one IP address.

Hope this helps.