>Hi All,
>
>I'm looking for some advice. I have an application that communicates between clients on individual PCs using UDP using the Winsock activeX control. It works fine, but I ran into a snag when trying to run the same application on multiple terminal server sessions. The first user's session grabs the UDP listening port and the other sessions get an error "port in use" when they try to launch, which makes sense.
>
>I'm exploring alternative methods of communication between the hosted sessions. An installation could have a mix of individual clients and hosted clients.
>
>I'd rather not use a timer or a file based method, as the message display on the clients needs to be synchronized as closely as possible. An event hook would be ideal. I was thinking of creating a system service specifically for Terminal Servers which could handle listening over the UDP port, but I'm looking for a good method of communicating between that service and the hosted clients.
>
>Any ideas or advice are greatly appreciated.
>
>-Matt

Is the communication peer to peer or server based? if its peer to peer, set up a server app with a known IP:Listen-PORT in the TS machine to which all clients connect to.

Use random listen-ports in each client when a client first connects, it sends its ID and IP:Listen-PORT to the server.

Have the server app keep track of the IP:Listen-PORT of each client. When communicating between 2 clients, you can use the server as a proxy that passes the data between clients, or a client first finds out the IP:Listen-PORT from the server of the desired client it wishes to connect to, then sends the UDP packets directly to that client.

You can even have clients gets a list of connected clients from the server.

Carlos