[69448] in North American Network Operators' Group
Re: TTY phone fraud and abuse
daemon@ATHENA.MIT.EDU (Steven M. Bellovin)
Sun Apr 11 22:05:40 2004
From: "Steven M. Bellovin" <smb@research.att.com>
To: Suresh Ramasubramanian <suresh@outblaze.com>
Cc: Sean Donelan <sean@donelan.com>,
Scott Call <scall@devolution.com>, nanog@merit.edu
In-Reply-To: Your message of "Mon, 12 Apr 2004 07:18:51 +0530."
<4079F583.3010200@outblaze.com>
Date: Sun, 11 Apr 2004 22:04:39 -0400
Errors-To: owner-nanog-outgoing@merit.edu
In message <4079F583.3010200@outblaze.com>, Suresh Ramasubramanian writes:
>[4/12/2004 4:49 AM] Steven M. Bellovin :
>
>> Naturally, miscreants (to use robt's terminology) try to find ways to
>> make such calls from the U.S. more cheaply. Sometimes, this involves
>> hacking PBXs, other times, it involves subscription fraud, or a variety
>> of other kinds of misbehavior. The responses are similar to those we
>> use on the Internet -- traffic analysis (similar to looking at
>> NetFlow), blacklisting calls to certain countries from, say, pay
>> phones, etc.
>
>There is another class of people who route calls out from the USA to
>India (or elsewhere) using VOIP, terminate the calls at an unauthorized
>(that is, not run by a licensed telco) exchange in india, and then route
>the calls out through the local pstn or mobile network.
>
>Quite a few of the "call $asian_country for cheap" phone cards you find
>at ethnic grocery stores seem to work on these lines.
>
>The local telco doesn't see a red cent of any settlement charges when
>this happens. Local telcos are, of course, all against this, and use
>any and every excuse to get these exchanges busted - a procedure that
>typically involves having the local police raid the exchange.
Yes. Depending on the countries and telcos involved, this is either
illegal or "irregular" network access. Other schemes involve call-back
(with the Internet as the signaling channel -- I first heard of that
being used in 1994, when most people outside our business had never
heard of the Internet) or calling through a third country if the
difference in rates makes that profitable.
--Steve Bellovin, http://www.research.att.com/~smb
