As Sean knows very well, the world of telephony fraud is very big and
very lucrative for the fraudsters. I don't work on that directly, but
I've had plenty of contact with people who do.
The big issue in the U.S. is international toll fraud -- calls to some
countries are very expensive because of artificially high settlement
charges imposed by the receiving countries' telcos (i.e., their PTTs).
In fact, for some Third World countries such revenue is a substantial
part of their hard currency income.
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.
The networks are different, so the types of fraud are different -- but
they occur, and they're very big business indeed. Note that U.S.
telcos are obligated, by contract, law, and treaty, to pay real dollars
to the receiving telcos, even if the call is fraudulent and the telcos
can't collect. At this point, domestic U.S. toll fraud is much less
interesting, because the real dollar outflow per minute for such calls
is generally a couple of orders of magnitude less. And then there are
900 numbers -- but that's another story for another day. Grab me in
the bar at NANOG some time...
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.
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.
One method that makes raids difficult is that the landing site for these
calls is often a satellite dish (for the international side) combined with
GSM phones (for the local side). Sure, you can cut off the GSM phones
one-by-one, but new ones are cheap enough that it's like a game of
whack-a-mole.
S
Stephen Sprunk "Stupid people surround themselves with smart
CCIE #3723 people. Smart people surround themselves with
K5SSS smart people who disagree with them." --Aaron Sorkin
The local telco doesn't see a red cent of any settlement charges when
this happens.
We all feel very sorry for them, I'm sure.
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.
One method that makes raids difficult is that the landing site for these
calls is often a satellite dish (for the international side) combined with
GSM phones (for the local side).
Wow, VoIP+sat+GSM, that must add up to close to 1500 ms delay! That can't be any fun.
Wow, VoIP+sat+GSM, that must add up to close to 1500 ms delay! That can't be any fun.
Well, there was a nanog thread some days back about voip over sat. People do it all the time (alaskan mining camps for example).
Voice quality is horrendous, there is some latency like you say.
People still buy these cards a lot as they get over a hour of talk time for a few dollars instead of the 10..15 minutes that you'd get with a comparably priced phone card from (say) MCI.
We will if they take it out on the local customers by raising the prices, or even worse, going belly up. Given the stability of some local telcos in 3rd world countries, this is not at all out of the question.