Black Box 32144, Руководство пользователя

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CHAPTER 4: General Operation and Special Features
• Manual-response password
protection (MPP). Remote
users attempting to connect to
the modem are required to
enter a password. Incoming
calls are accepted only if the
user enters a valid password.
4.11 Automatic Password Protection
(APP)
The modem can be configured for
two types of APP:
• APP without callback—The
modem can be configured so
that each time it receives a
connect request from another
modem, it automatically
employs a security handshake
that includes a user-assigned
password. Connect requests will
be accepted only from modems
that have been programmed
with the same password. APP
without callback functions in
any operating mode that uses
trellis coding (normally 72, 090
bps and above).
• APP with callback—This type of
password protection is the same
as described above, except that
the answer modem connects
with the originating modem by
calling it back. The connection
can only be made if both
modems are preprogrammed
with the same password and if
the answer modem is
preprogrammed with the
number of the originating
modem (the callback phone
number). APP with callback is
for dialup applications only
(synchronous or
asynchronous).
Test Interval (Test)
If the Return option has been
enabled (10, 40, 60, or 120 s), the
Test Interval selections control how
frequently the modem will test the
leased line conditions to determine
if exit from the Leased Line Auto-
Recovery mode is desirable (based
on the criteria selected for return
from Auto-Recovery). The modem
can be set to test every 10, 20, 40,
or 60 minutes.
NOTE
The Test option setting must
be the same on both units.
4.10 Modem Security Operation
NOTE
Security features described
in this manual provide a
deterrent to unauthorized
access. No communications
system can be made
perfectly secure.
Two types of security operation
are available to screen incoming
calls:
• Automatic password protection
(APP). Users do not have to
enter a password, but both
modems must be correctly
configured to exchange the
same password (as part of a
security handshake), or they
will not be able to connect.