General DataComm 060A027-001, Руководство по установке и эксплуатации

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Operation Security Overview
060R122-000 SpectraComm Dual V.34 Modem 3-11
Issue 15 Installation and Operation
SteadFast Password Security
For all types of SteadFast Security, both modems must be GDC modems optioned for SteadFast
Security (
%S1 ). The same SteadFast password (up to 10 characters) must be stored in both modems
in memory cell 0 ( %P0= xxx, where xxx is the cell password). The remote user does not have to
enter additional cell passwords. As part of the SteadFast handshake sequence, the answering
modem verifies that the password stored in its cell
0 matches the password stored in cell 0 of
the answering modem. This sequence guarantees that unauthorized users are denied a connection to
the modem and the network. The three SteadFast Security options are described below.
SteadFast Security with Pass-Thru
When the remote caller initiates a call, the answer modem attempts to match the passwords stored
in cell
0
of both modems during the handshake. With a match, the answer modem directly admits
a caller using a valid cell password. If an invalid cell password is entered, the answering modem
terminates the call.
SteadFast Security with Callback
A remote user initiating a call can invoke the callback feature by including the AT dial command
modifier
\
n , where n represents a phone number cell in the answering modem. The dial
command modifier, when combined with the valid SteadFast Security password, causes the modem
to disconnect the incoming call and dial the number from the specified memory cell. The callback
phone number must be saved in a phone number cell of the answering modem by means of the
&Z
n
=
nnn command. Up to ten phone numbers can be stored in memory cells
0
through
9
using
the
&Z
command.
Example: To call a modem at 555-1212 and have it call back the phone number stored in cell 1 ,
enter the following modem command:
ATD5551212\1
After handshaking and a short delay, the remote modem terminates the call, and places a new call,
using the phone number stored in cell
1
, back to the modem that initiated the process. If the dial
command modifier had not been included, the SteadFast Security cell password would have
resulted in a pass-thru connection.
SteadFast Security with Mandatory Callback
The answering modem can be configured for SteadFast Security with a Mandatory Callback by
using the
%S4
command. The calling modem must be optioned for
%S1
and a callback phone
number must be saved in the answering modem by means of the
&Z
n
=
nnn command.
To initiate a connection, the caller must include a valid callback cell number with the phone number
that is dialed.
Example:
ATDT5551212\1
If the callback cell number is not supplied with the phone number, the answering modem will
disconnect the call.
Note
Security callback telephone numbers should always include the Retry modifier [:n] to compensate for
any delay in receiving the dial tone from the Central Office after the initial connection is terminated.
Configure the modem to make at least three additional attempts to dial the number. If calls abort during
handshake, try disabling character abort feature (
%K1
).
Note
When both SteadFast Security and Online Security are enabled and callback is also desired, the modem
should be configured for Online Callback and not SteadFast Callback. Otherwise, the callback function
will be blocked.