Great Circle Associates Firewalls
(January 1997)
 

Indexed By Date: [Previous] [Next] Indexed By Thread: [Previous] [Next]

Subject: Re: [Fwd: Internal modems ?]
From: "Patrick O'Callaghan" <poc @ usb . ve>
Date: Thu, 30 Jan 1997 08:09:40 +0400
To: Firewalls @ GreatCircle . COM
In-reply-to: Message from Patrick Larkin Jr <plarkin @ iphase . com> of "Wed, 29 Jan 1997 15:52:48 CST."

Patrick Larkin Jr writes:
>Pierre-Yves Bonnetain wrote:
>Well, *I* used to run a "war-dialer" over all our DID numbers
>that were NOT known faxes/modems.  Now, we have a Northern 
>Telecom with mostly digital lines, so modems can't easily 
>be attached.  What I REALLY want is some software that sits
>in the PBX, "listens" to calls enough to detect if there's
>a modem talking on a line that should be voice only.... then
>tear down the call if there is.  I've heard of such a thing,
>but NorTel is clueless.  Anyone know of such a package?

Random thought: would it be possible to insert a (hardware) filter
on incoming lines to block modem signalling frequencies? This would
not disturb voice traffic but might be an effective solution. Modern modems
of course use a whole spectrum of frequencies in parallel, but all you
would need is to prevent the initial protocol negotiation, which is
much more fixed.

Or am I totally clueless?

Patrick (Not At All A Hardware Expert) O'Callaghan
-- 
Prof. P. O'Callaghan			Internet: poc @
 usb .
 ve
Departamento de Computacion		NICNAME: PO22
Universidad Simon Bolivar 		Tel: +58 (2) 906-{3241,3242,3254}
Caracas, Venezuela			FAX: +58 (2) 906-3243
(Ask for my full postal address)	"Errare uHmanum Est"



Indexed By Date Previous: MS Proxy as a firewall?
From: Mike Blaser <Mike @ scio . demon . co . uk>
Next: Telnet - rlogin - klogin
From: "Leon O'Brien" <leon @ networx . com . au>
Indexed By Thread Previous: Re: [Fwd: Internal modems ?]
From: Adam Shostack <adam @ homeport . org>
Next: Re: [Fwd: Internal modems ?]
From: peter @ baileynm . com (Peter da Silva)

Google
 
Search Internet Search www.greatcircle.com