Question : Port Forwarding

I have a TP-link 8810 modem router.
My windows server 2003 has the local ip of 192.168.1.200
and a local WAN  Ip address of 192.168.0.1 (for modem)
the modem is 192.168.0.10

and the term server is 192.168.1.5
I need to port forwart to the term server 192.168.1.5
I set port forward 3389 to 192.168.1.5 and nothing happens remember the modem is 192.168.0.10
is this a restriction with these budget modems?

Answer : Port Forwarding

This is not really possible, if I correctly understand your configuration. It is not a modem/router restriction. I assume you have:

Internet=>Modem=>192.168.0.1-server-192.168.1.200=>switch=>192.168.1.5-server

If so all traffic is routed through the server. You would need to forward traffic to the 192.168.1.200 server, configure routing (RRAS) on that server, and then forward the traffic on to the 192.168.1.5 server. 2003 is not really designed to forward traffic by port.
 
-If you have Small Business Server 2003 this can be accomplished with Remote Web workplace.
I-f not, and you only need management capability, you can connect to the 192.168.0.200 server using Remote Desktop, and from there make a remote desktop connection to the other server.
-If it is a true terminal server, and you want to set it up for everyone to access it, I would change your primary server to use a single network adapter, then all units would be on the same subnet. You would need to make sure there is a firewall between it and the Internet. Based on the IP of your modem, I assume it is a combined modem and router/firewall. Doing so would result in:

                                                |+>192.168.1.200-server
Internet=>Modem=>switch=>|
                                                |=>192.168.1.5-server