>We are looking at setting up a VPN using the Cisco 506 firewall to let remote users run a VFP 7.0 application. Our internet connection is a fractional T1 line and the server is a high end Pentium III. Perhaps up to 20 concurrent users.
>
>Has anyone done something similar and if so, how is performance and stability?

RAS on fractional T1 will significantly underperform a LAN connection; remember, potnetially, you're dividing a fraction of 1.544Mbps among the currently active connections, rather than the nominal 10Mbps of an EtherNet or 100Mbps of Fast EtherNet, and have significantly increased latency, which results in slower connection turnaround time. If you really need to operate under VPN, I'd look at implementing TerminaL Server and making the TSAC available across VPN instead.