Hive: HKEY_LOCAL_MACHINE
Key: SYSTEM\CurrentControlSet\Services\RemoteAccess\Parameters
Name: AuthenticateTime
Type: REG_DWORD
Value: 20-600 seconds
Sets the maximum time limit, in seconds, within which a user must be successfully authenticated. If the client does not complete the authentication process within this time, the user is disconnected. Default=120 seconds.

RAS Tips:

Alert - Win98 2nd Edition now supports 128-bit encyption Q244214
Auditing
Autodisconnect interval
Callback interval
Determine in Logon Script Whether Client Is Connected by RAS or LAN
Disable DUN's Save Password option
FAQs: Dial-Up Networking and RAS Questions technote Q162293
Log connections
log PPP connections
Max unsuccessful logon attempts
Max time limit to successfully logon
NetBIOS gateway
Prevent connections from closing when logging off
Remove Dial-up Logon Checkbox
Rings, Control number of rings before RAS server answers
Troubleshooting PPTP Connectivity Issues in Windows NT 4.0Q162847
User Cannot Log On to LAN Because of RAS Logon Failures Q177125

Book Recommendations: