> Would "keep TCP/IP connections open" be the same as persistent > connections?
Yes, although TCP/IP itself does not have a mechanism to confirm a connection is still open, except possible keep alive packets. Normally you only find out a connection has disconnected when trying to send something, and getting a timeout error. It's best for your protocol to send a packet back and forward every minute or two, so both ends know the connection is alive. My large application updated a SQL database with this, and had web pages to review which clients were online. The keep alive packet also sent the server time to ensure clients were synchronised, and the client sent back status information, temperatures, etc. When dealing with large number of connections, apart from server memory, you may have firewall issues, you have to think big. BTW, there are several client/server samples, but start with OverbyteIcsTcpSrv and OverbyteIcsCliDemo, or use my 'IP Log Streaming Component' from: http://www.magsys.co.uk/delphi/magics.asp which should allow you to prototype something in a couple of hours. Angus -- To unsubscribe or change your settings for TWSocket mailing list please goto http://lists.elists.org/cgi-bin/mailman/listinfo/twsocket Visit our website at http://www.overbyte.be