W2K Term Ser. and Linky Router

I’m trying to set-up a W2K Term Serv behind a Linky (befsr11) router. The ‘helpful’ people @ linksys had me try about 100 different things, with no response. The machines trying to access the term serv get a ‘server too busy’ message when trying to connect. They can, however, connect to our ISP’s term serv. We can also access the term serv locally so it’s a matter of getting thru the linky. Please help.