Multi-Tech MT9234ZBA Series, Руководство пользователя

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Chapter 5 – Callback Security
This chapter describes how to use callback security with your modem. Callback security protects your network
from unauthorized access and helps control long ‐ distance costs. When callback security is enabled, all callers are
requested to enter a password. If a valid password is received, the modem hangs up and returns the call by
dialing a phone number that is stored with the password. The person being called back must then enter the
password a second time to establish a connection.
Up to 30 callback passwords and dialing strings can be stored in the modem. Each dialing string can be up to 34
or 35 characters long and can contain commands as well as phone numbers. For mobile callers, the dialing string
can be programmed to allow the caller to bypass the stored callback number by entering a temporary callback
number, to enter an extension at the callback number, or to make a direct connection without callback.
For local security, the passwords and dialing strings that are stored in the modem are protected from tampering
by a setup password, which you should change when you set up the modem. You can further protect the
modem against tampering by disabling its ability to respond to most AT commands. To check for attempted
break ‐ ins, you can request the modem to display the number of failed password attempts.
Your modem was shipped with a default setup password (MTSMODEM). The same password is used for both
callback security and remote configuration (Chapter 4). Because anyone who has access to this guide has access
to the default password, you should change the password during your initial setup.
Changing the Setup Password
1.
Open a data communications program such as HyperTerminal.
2.
In the terminal window, type AT#SMTSMODEM (or AT#S xxxxxxxx if you have replaced the MTSMODEM
password with xxxxxxxx ). Press E
NTER
. The modem responds with OK if the setup password is correct and
ERROR if it is wrong.
3.
To change the password, type AT#S= xxxxxxxx , where xxxxxxxx stands for the password, and then press
E
NTER
. The password can include any keyboard character, and can be up to eight characters long. The
modem responds with OK .
4.
The new password is saved automatically. You can now either enter more AT commands or exit the data
communications program. The next time you wish to set up the modem, you must use the new password.
Note: Passwords are case ‐ sensitive.
Turning Callback Security On and Off
Callback security must be turned on to enter many callback security commands.
1.
Open a data communications program such as HyperTerminal.
2.
In the terminal window, type AT#S xxxxxxxx , where xxxxxxxx is your password. Press E
NTER
. The modem
responds with OK if the setup password is correct and ERROR if it is wrong.
18 Multi ‐ Tech Systems, Inc. MT9234ZBA ‐ Series User Guide