If you haven't done so yet, you may want to consider researching Citrix Winframe (www.citrix.com) which my company utilizes. We achieve acceptable performance over a 128k (fractional T-1) frame relay connection between our Florida and California offices. The reason why is that Citrix only send the screen updates to the client workstation and print jobs; their technology has been incorporated into NT 5.0 by MS for the Windows Terminal, a.k.a. Hydra.

At any rate, this is one way to go thin client without web enabling your app or even going n-tier. I think it would be well worth your time research the product...

Good luck...

Jack Mendenhall
Manager, Information Systems
Reinsurance Management, Inc.



>I am currently exploring ways to WAN enable a VFP application that is currently under development.
>
>After experimenting with a VPN over a 56K frame, I have demonstrated that VFP uses "wiser" data access methods by directly opening the tables than it ever will using ODBC and remote views. For example, even if I have it set to fetch as needed and retrieve in background with a fetch size of 20 records, all 40,000 records are actually passed over the data connection BEFORE control returns to VFP. Now, at this time the cursor only has 20 records in it, and true, it loads data 20 records at a time as I scroll down a browse, but all the data has actually already been passed over the connection.
>
>Conversely, VFP actually handles its data in a smarter fashion. Only loads the index when a function call that uses an index is invoked. Only loads data by needed "sets". For example, if I browse a table the top (approx 20 - 40) records are read accross. If I GO BOTTOM, the bottom 20-40 are read accross, but the middle 41,900++ still have not been read in.
>
>Unfortunately, directly opening/accessing tables will not be an acceptable solution because it is also too slow. It would go down to "sluggish" over a T1, but it is uncertain if clients will pay for T1 lines to have a "sluggish" app.
>
>Questions:
>
>1) Is it a valid assumption that a 1.5mb line (T1) would be about 6-7 times slower than the 10BaseT LAN (discounting latency)?
>
>2) Does anyone know of any successfull implementations of three-tier solutions with an accent on limiting data throughput over the network?
>
>3) Does anyone have ANY suggestions as to implementations, approaches, etc that I should pursue.
>
>4) Do SQL Server ODBC drivers actually work "as expected" with remote views (unlike the VFP ODBC driver)? I am willing to consider putting the data store into SQL Server for an "enterprise" edition of the app if necessary (read "aarrrrgghhh").
>
>A web interface is not really an option due to the complexity of the data involved. It would REALLY SUCK under this implementation.
>
>I am interested in referrals to reading material, technical papers, new ideas, and perhaps best of all, a three-tier framework if one exists.
>
>Thanks very much in advance,