Re: Modem Security

From: zcat@themall.co.nz
Date: 06/13/02 

Date: Thu, 13 Jun 2002 10:15:07 +1200 (NZST)
From: <zcat@themall.co.nz>

> Well, here's an idea. It depends on the type of phone system you have
> and whether or not your user needs inbound dialing. Most phone systems
> are PBX types that are pretty configurable. Make the modem line an

PABX or not, most teleco's will let you do call-diversion to another line
or have some kind of answering service. If inbound calls never go to that
line, you can be fairly confident that the modem won't be answering them.

It shouldn't really be a problem in the first place; check that the modem
isn't answering calls (by calling it) which is normally the default
behaviour. If it is, switch the feature off and beat the errant user with
a clue-by-four. Divert all incomming calls elsewhere just to be sure.

Presumably outbound calls are direct to the legacy service and not using
TCP/IP in any way (otherwise your user could presumably contact the same
service via the internet) so shouldn't present any risk.

One other thing to be aware of; there are a few 'dialler' programs out
there that will phone Muldovia when you're not watching, any machine with
a modem in it could be at risk. If your PABX allows it restrict outgoing
calls on that extension as far as possible just in case.

Relevant Pages

  • RE: [Full-Disclosure] Mystery phone lines, something is hiding and answ ering.
    ... There is usually a modem into the phone system for ... Michael R. Schmidt ... I generally start at the equipment, (CC machine, FAX, Modem, etc) and get ... Charter: http://lists.netsys.com/full-disclosure-charter.html ...
    (Full-Disclosure)
  • Voice Modem not connecting.
    ... An application using TAPI dials an extension on an internal phone system, then plays an audio file. ... but in this location the modem doesn't seem to connect. ...
    (comp.dcom.modems)
  • Re: Poor Fax Line Quality?
    ... tone from the phone system and we still had problems. ... modem to a USR and I still had problems. ... serious about faxing then either brand would be more likely to work. ... Problems with the consistent set of senders... ...
    (microsoft.public.windows.server.sbs)
  • Re: Digital Line Detect
    ... A PBX is generally associated with a phone system that can switch between ... digital signal...a modem does the same thing, but a modem on a digital ... > directly connected to a standard analog modem or fax line". ...
    (microsoft.public.windowsxp.perform_maintain)