AT Commands and S-Registers
4-27
3825-A2-GB30-20
November 1996
Security
Security configuration on the 3825Plus modem is
performed using the AT commands and S-registers in
Table 4-3.
Password Types
Security in 3825Plus modems is implemented with
three basic types of passwords.
There is one Administration Password which permits
access to the password list and other security
configuration options. When the modem is shipped the
Administration Password is 00000000. The Reset Security
(%SR) command changes the Administration Password to
the value shown on the last page of this manual. It also
can be changed with the Change Administration Password
(%SA=) command.
VF passwords consist of DTMF tones and are entered
by the originating caller using the AT Dial (D) command,
or the keypad of an attached telephone. They must consist
of eight decimal digits, 0 through 9, and are terminated
with the # symbol. For example, if 11223344 is a valid VF
password on the 3825Plus modem at the telephone
number 555-4321, it can be accessed with this command:
ATDT555-4321@11223344#
If pulse dialing must be used, the VF password must
still be sent in DTMF tones. This can be done using a
combination of P (pulse) and T (tone) dial modifiers:
ATDP555-4321TW11223344#
The requirement of the @ (wait for quiet answer) or
W (wait for second dial tone) dial modifier depends on the
value of S-register S95. For more information about dial
modifiers, see the Dial (Dn) command.
DTE passwords are entered by the originating caller
from the DTE keyboard. They may consist of six
characters, and may be a combination of decimal digits 0
through 9 and the letters A through Z (upper or lower
case).
Up to 20 VF and DTE passwords can be stored in the
password table in the memory of the 3825Plus modem.
Each password is indexed by a number, 1 through 20. The
index number is used when displaying or changing a
password.
Originate Security
An Originate Access password is entered by a local
user to gain access to a local 3825Plus modem. This
password must be embedded in the AT dial command.
The password must be defined as a DTE_Entry type in the
password table.
The following example describes how to enter an
Originate Access security password:
TYPE:
ATD%C2C3D2%T18135551234
PRESS:
Enter
Where:
ATD is the AT dial command.
% is the start and stop dial string
command interrupt characters; the
Originate Access password must be
enclosed by these characters.
C2C3D2 is the alphanumeric 6-character
Originate Access password on the local
modem.
T is the Tone (DTMF) dial modifier.
18135551234 is the phone number of a
remote modem.
Answer Security
DTE passwords alone, or a combination of both VF
and DTE passwords, may be used for Answer Security.
With VF and DTE Security, modems negotiate VF
password entry before training. If successful, the modems
connect and then prompt the user for a valid DTE
password.
Another combination is called VF with DTE Security.
In this case, the modem will accept as valid only the DTE
password whose password table entry immediately
follows that of the VF password that was received. For
example, if the VF password at index number 9 is used to
connect, the DTE password at index number 10 is the
only valid DTE password.
The command used to add a VF password (%SV or
%SB) determines whether combination security is used.
S-register S68 determines whether VF and DTE Security
or VF with DTE Security is used.
