At this time, only Windows client setups are described here. On the client PC, a COM-port redirector for TCP/IP is required. The best program for this purpose I have found is DialOut/IP from Tactical Software for Windows 3.1 and Windows 95. (The Windows 3.1 version can be used under Windows NT for 16-bit applications only. A 32-bit version for Windows NT is due late summer 1997.)
DialOut/IP presents the shared modem on a new virtual COM port that it adds to Windows. This virtual COM port can be used by Windows programs as if the shared modem is directly connected. Most client applications (including Windows 95 dial-up networking) accept this and work as if there were a real COM port and modem, with the general exception being fax applications or any others that need access to UART control lines. DialOut/IP can be configured to provide telnet protocol processing, but that feature applies to certain modem pool products and not to the Linux setup described in this file. Note that, despite its name, DialOut/IP can be used also by applications that wait for incoming calls.
On http://www.tactical-sw.com/ there is a page for downloading a fully functional evaluation version that times out in 1-2 weeks. Installation and configuration is handled by a setup program, with installation details in the README.TXT file. When you run DialOut/IP, you enter the IP address and port number of the shared modem.
DialOut/IP is a commercial product that is licensed on a per-modem basis, that is, the price depends on the number of modems that you are sharing. The license states that you can install the software on any number of PC's that access the shared modems.