User's Guide for MS-DOS Clients

346
Using Remote Access Service
Modems
If you decide to enable error control and/or compression, first check the
following:
• Make sure your workstation can accommodate the higher baud rates required for
compression. Your RAS client workstation must have a 80386 or higher proces-
sor and also have 16450 or higher serial port chip installed.
• Make sure your RAS server has a multiport adapter installed, relieving the main
processor of some of the interrupt processing load.
• Make sure your modem has the large buffers needed to increase the DTE speed
without enabling flow control.
• Make sure you have identical or compatible modem types on the server and client
workstations.
• Make sure your telephone line has little or no static. This minimizes the impact
of redundant error control.
To enable modem error correction and/or compression
1 Set the MAXBAUD parameter for your modem in the MODEMS.INF file to the
maximum baud rate at which you will be communicating. Valid baud rates are
1200, 2400, 4800, 9600, 19200, and 38400.
2 For MS-DOS workstations running LAN Manager Enhanced, change digit 14 of
the wrkheuristics line in the LANMAN.INI file from 1 to 0. This causes the
LAN Manager workstation to transfer data in 64K blocks. This large block size
ensures a smooth, constant flow of data from the computer to the modem. The
modem’s compression buffers will fill up quickly, thereby minimizing data trans-
mission delays.
NOTE: Microsoft cannot guarantee proper functionality at baud rates higher than those
indicated in the default MAXBAUD = line of your MODEMS.INF file.