My guess - random. Try http://www.sysinternals.com/ntw2k/source/tcpview.shtml. Launch TCPView and then your app. I think you'll see a different port in use each time.

>Recently I was able to review a product called Packeteer. This product sits on the network and analyzes bandwith to the application level. Some versions even let you shape or dictate how much bandwith an application gets. In the conversation I was asked what port my VFP application was written for. I have no idea. Does any one no what port VFP applications are written for?