Non-Password Auto Call Back Function - ZyXEL Communications omni TA128 User Manual

when the TA128 is shipped from the factory. This supervisory
password is sent to the remote if Type 1 security is set at the
remote end.
To modify the supervisor password, use AT*HS.
You will be asked for the original password and a new password.
Then re-enter the new password for verification. For example:
Password:
******** (Enter current supervisory password)
Password:
******** (Enter new supervisory password)
Verify:
******** (Enter the new supervisory password again)
OK
Use command AT*Hn to modify the "n"th user password. You
will be prompted to enter the supervisory password first and then
the user's password for this entry will be requested and verified.
The command AT*V will list the 40 user passwords and the
supervisor password on the screen for viewing.

Non-password Auto Call Back Function

In addition to the standard modem-like security functions
described in the previous section, the TA128 provides another
simpler call back function. The Calling Party Number (origination
address) will be checked against the 5 pre-stored call-back numbers
before the B channel is connected. If the CPN is matched with any
one of the numbers, the incoming call will be rejected (without
connection, hence without any charge) and the TA128 will
automatically call back using the matched phone number.
This function can be controlled using the following commands:
AT*GC0 - disable the auto call back function (default).
AT*GC1 - enable the auto call back function.
The pre-stored numbers can be set using the following command:
91