Paradyne COMSPHERE 3920PLUS Series, Техническое справочное руководство

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Dial Access Security
12-3 3920-A2-GH30-40 October 1998
VF-Side Passwords
VF-side password entry occurs between modems prior to connecting. Once the VF-side password
is entered, no other user intervention is required since security negotiation is handled solely by the
modems. When the answering modem is configured for VF entry technique, it goes off-hook and
transmits to the originating modem either a secondary dial tone or silence (this choice depends on
how the VF Prompt Type option is configured). The originating modem detects this response and
transmits its password which corresponds to a preselected series of DTMF tones. Note that VF
passwords can be from 1 to 8 digits in length; only decimal digits are permitted. The answering
modem verifies the password against its own password database, and if valid, continues with the
normal training sequence.
VF-side password works with any autodialer that supports second dial tone or quiet answer and
can be implemented in one of three ways. First, the VF password can be embedded within the AT
command dial string. Second, a phone number and password can be entered via the diagnostic
control panel (DCP). (This is the preferred method for synchronous applications.) And finally, an
attached telephone can be used to manually generate DTMF tones for the phone number and
password. After the answering modem accepts the password and generates an answerback tone, the
originating caller places the modem in Data mode and hangs up the phone.
The following examples illustrate two ways to enter a VF-side password:
ATDP5551234TW12345678# or ATDT5551234@12345678#
Where: ATD is the AT dial command.
P and T are the Pulse dial and Tone (DTMF) dial modifiers.
5551234 is the phone number.
W or @ is the VF Prompt Tone option setting for second dial tone or quiet answer.
12345678 is the VF-side password.
# is the password termination character.
NOTE
While pulse dial can be used to originate the call, DTMF tones must
be used for the password. This can be accomplished by using the P
and T modifiers appropriately. Refer to the Dial command in
Chapter 14,
AT Command Set and S-Registers , for more on
modifiers.
This method of password entry requires that the answering modem be a 392xPlus modem. Of
course, the 392xPlus modems must be configured for VF-side password entry and the originating
user must know the correct VF-side password. The originating modem can be another 392xPlus
modem or any vendor’s modem.