Reference Guide for the Model XM128 ISDN Digital Modem
B-2 Security Functions
The two types of security are summarized in TableB-1.
Level 1 Security
This security level performs only password checking. With Level 1 security, the local modem
maintains the connection if the password is matched. Otherwise, the line is disconnected.
Level 2 Security
Level 2 security provides extra calling party number (CPN) checking and callback. The callback
number is prestored in the password table. If the password has been matched (in a maximum of
three tries over a 40-second time period) with its prestored password list, the local modem checks
the calling party number (or origination address for 1TR6) against the prestored number
corresponding to the password. If they are matched, the local modem chooses either to keep the
connection or to disconnect; then it calls back according to the following settings of bit 6 of S119:
• S119.6=0
This setting prompts the modem to connect and then to call back.
• S119.6=1
This setting prompts the modem to keep the connection.
If the CPN does not match what is stored in the table, the local modem disconne cts the call. If CPN
is unavailable in the setup message, the local modem disconnects the call and calls back using the
prestored number corresponding to the dial-in password.
TableB-1. Types of security
Type 1 Security Type 2 Security
Remote (Calling) Site NETGEAR ISDN device only Can be modem of any brand
Password Check Automatic Interactive
Protocols Supported X.75, V.120 Any data protocol
AT Commands *G1 for Level 1 security
*G2 for Level 2 security *G 3 for Level 1 security
*G4 for Level 2 security
*G5 for Level 3 security