A client/server application

Hi!!
I'm developing an application that is client and server at the same time - now I explain how it could work:
the application listens a request on a tcp port from a remote client; when a client make a request, the application make a
connection to another device and finally links them (remote client with the device).
I developed the simple client and server application, but now
I have to put them together to realize the client/service application that listens to the remote requests and "forward"
by linking the remote clients to other devices (such as router).
Can You give me any advices about how I can realize this "linking" procedure of the application??
Thank You!!
Christian

Have a look at this sample code
C:\Program Files\Borland\Delphi6\Demos\Internet\Chat