The setting in the Database Properties for Client/Server Connections Timeout is the same setting that can be customized using the ".opt" files in the ACI directory. Except, of course, that one is entered in minutes and the other seconds. We advise you to use Customizer Plus for best results (leaving the database properties set at its default), for convenience you can place a modified .opt file on a network file server and then simply copy it onto each machine as needed without having to run Customizer every time. If you set the Timeout value to zero in Customizer Plus that indicates "No Timeout".
If you set the .opt file to No Timeout on the server, you'll notice that clients who crash or lose their connection to the server will never get dropped from the list of active processes (and may stop users from re-logging into the server until someone manually kills their old process). If you set the .opt file on the client to No Timeout, you will find that the 4D Client software will "hang" as it endlessly tries to reestablish a dropped connection to the 4D Server (as an experiment, try pulling the network cable out from a connected client machine that has been set to No Timeout). You will only see this behavior if the 4D Client is idle when the network disruption occurs - if there is active communication to the server (i.e. the user is performing some activity) and there is a network disruption then both 4D Client and 4D Server should recognize the problem and produce a -1000x error.
NOTE: If you set the 4D Server to No Timeout, you will also want to set the 4D Clients the same way. There is nothing to prevent you from breaking this rule in Customizer Plus or the DB Prop., but if you do not set them the same they will not respond to each other properly and you may end up with NC errors. In fact, we recommend that you set the server and all clients to the same value for best results. If you set a non-zero value for the Timeout on the 4D Server CPU, then set the clients to a value that is approximately 10% greater (for example 10 mins on server and 11 mins on clients).
Much of the difficulties in the Network Components under Windows is due to the way that the networking protocols (IPX or TCP) are implemented differently than on the Mac OS. There is less frequent communications on the Windows platform, thus the need for the new timeout setting for 4D Server & Client. If TCP and IPX just won't work reliably for you on your network, there is another option which is to use the AppleTalk protocol for communications. Windows NT Server comes with AppleTalk support as an additional installable option. Unfortunately, Windows 95/98 does not ship with AppleTalk support but it is available from 3rd parties like Miramar Systems.
Network Components - Reference Manual
Customizer Plus - 6.0 and 6.5 Reference Manuals
(See Chapter 8: "Customizing Network Components")