Control number of rings before RAS server answers

Need that RAS server to ring more than once before answering? There are two ways
to do it, depending on the type of modem you have. The normal method is to edit
the file %systemroot%\system32\ras\modem.inf. To edit the file, locate the
sections relating to your modem and find the line:

COMMAND_LISTEN=ATS0=1

Change the numeric value from 1 to the desired number of rings. For example,
if you want the RAS server to wait for six rings before answering, simply edit
the line as follows:

COMMAND_LISTEN=ATS0=6

You must restart Windows NT for this change to take effect.

Note that the above method doesn’t work if RAS is using any TAPI (Telephony
Application Programming Interface) or Unimodem-based devices. If this is the
case perform the following registry tweak:

Hive: HKEY_LOCAL_MACHINE
Key: SYSTEM\CurrentControlSet\Services\RasMan\Parameters
Name:
NumberOfRings
Type: REG_DWORD
Value: 1-20
rings