Rating engines of telecom billing systems are built on A-B number
analysis, that is they check out where a call is coming from based on
the A-number (originating number) and where it goes to based on the
B-number (terminating number). Billing systems for mobile networks also
often include cell-site ID in their rating tables in order to allow for
discounted tariffs based on where the mobile is at the time of the call.
In any event, the B-number is looked up based on its area code and any
two numbers with the same prefix are not normally distinguishable for
charging purposes by the rating engine. All 03 numbers are generally in
the same tariff group. There are some techniques that allow for
discounts (i.e. closed user group membership) and tariff groups could be
broken down further, i.e. 03-5xxx-xxxx is a different tariff group than
03-3xxx-xxxx, but the principle remains.
Therefore, premium rate numbers are given special area codes to create a
new tariff group, i.e. 0990 in Japan. This, too can be broken down
further in order to allow for different tariffs, i.e. 0990-1 for tariff
1, 0990-2 for tariff 2 etc etc.
If you wanted to make a particular number in a local tariff group into a
premium rate number you would have to override the ordinary rating rules
by way of translating that number into a premium rate number. This may
be possible within the rating table, but more likely you would have to
do this on the switch level, that is, you would need to configure the
exchange to convert the B-number into a 0990 number so that the rating
engine will treat it as a premium rate number. But even if you did that,
there would unlikely be any tariff group with a charge as high as
suggested. In most countries the maximum charge for premium rate
services is fixed by law or by regulation.
Furthermore, even if you manage to overcharge in this way, there would
still be the problem how the holder of the B-number would benefit from
the charges incurred. This is because that number is within the domain
of the wireline provider (probably NTT) and they need to claim charges
through inter-carrier settlement, a process outside of the domain of
each company's retail billing systems.
In other words, you would have to
a) modify one or more exchanges in the mobile phone network
b) modify the rating table of the mobile phone company's retail billing
system
c) modify the rating table of the wireline carrier's inter-carrier
billing system
d) probably modify or disable alerts on both company's fraud detection
systems
e) if a clearing house is involved, modify tariff tables in the clearing
house
A scam that involves that many different fraudulent actions over
multiple departments in more than one company is rather unlikely in
Japan. In Africa, yes, those things happen anyday everywhere. African
telcos are an auditor's paradise (or nightmare depending on viewpoint),
but Japan ? Also, if it was indeed a scam, would they make it that
obvious ? Probably not. They'd put a small charge there so that people
wouldn't necessarily notice and complain.
Well, ok, never say never, fair enough. But instead of a well organised
multi-company scam, at first sight, I would assume that something like
this happening in Japan is due to a weird coding error or data
corruption in the mobile phone company's rating engine respectively its
rating tables. Having evaluated Japanese built telecom billing systems,
I wouldn't be at all surprised if this was a glitch in some COBOL
mask ;-)
Come to think of it, COBOL uses "09999" to denote a mask for a four
digit number with a leading zero (IIRC), so it might well be that
somehow one of these masks "0990" made it into the wrong place and in
combination with one of those famous COBOL patches anything might
happen. I don't know if DoCoMo, or NTT use COBOL in their rating
engines, but even if they don't, out of tradition, they might be using
some other CODASYL conforming tool somewhere in the processing chain, in
which case the chance is that even fewer people will understand what it
does and how it is supposed to work.
rgds
benjamin
On Saturday, December 1, 2001, at 02:12 , Jason Pollard wrote:
> How can it cost so much to connect to a 03* number? They're Tokyo
> local,
> right? Not on Mars I assume. Does the party on the other end have
> some method
> to decide how much you the caller have to pay to connect? Seems like
> the
> providers are partly to blame in this scam. Nobody's actually having
> to pay
> that amount, I hope. If I had an i-mode phone, I'd call each number in
> the
> list, several times, just to see how high I could rack up the
> charges...Storm
> into the office with a million yen phone bill...start raising some
> serious
> gaijin hell....
>
>
> --Jason
>
>
> --- Marc Printz <Marc.Printz@724.com> wrote:
>> I think its more an interesting hoax actually.
>> A hoax following precisely the same pattern went around in Germany last
>> month or so.
>> Different phone numbers though :-)
>>
>>
>>> -----Original Message-----
>>> From: Thomas O'Dowd [mailto:tom@nooper.com]
>>> Sent: Friday, November 30, 2001 3:28 PM
>>> To: Keitai List
>>> Subject: (keitai-l) interesting scam
>>>
>>>
>>> Hi all,
>>>
>>> We were talking about spam email before and then got onto the subject
>>> of cases where you're phone would ring once and when you'd call the
>>> number back, you'd get a message. Well, it seems to be becoming a bit
>>> of a problem... 100,000 yen ouch!
>>>
>>>> Problem: Extremely high charge (reportedly approx. JPY 100,000 per
>>>> call) which is very difficult to recover.
>>>>
>>>> Description: You receive a call from one of the numbers on
>>> the list (a
>>>> number is displayed upon receipt) which hangs up on the
>>> first ring or right
>>>> after you pick up the call, leaving an entry in " Received
>>> Record ". Calling
>>>> back to this number, intentionally or inadvertently, even
>>> for a fraction of
>>>> time imposes a large amount of usage charge on your bill
>>> (Once connected,
>>>> you will hear a tape-recorded voice message).
>>>>
>>>> Numbers identified as part of this scam:
>>>>
>>>> 03-3227-2828 03-3984-6761 03-5724-2929
>>>> 03-3280-7660 03-5340-8877 052-733-1288
>>>> 03-3355-7550 03-5340-9330 052-733-1551
>>>> 03-3444-6555 03-5340-9381 052-733-8488
>>>> 03-3444-6710 03-5340-9382 052-735-7300
>>>> 03-3446-0990 03-5348-4441 0534-27-3172
>>>> 03-3446-4567 03-5391-7600 06-4968-3114
>>>> 03-3448-4760 03-5420-4466 06-6300-0702
>>>> 03-3551-4330 03-5423-2570 06-6301-1999
>>>> 03-3793-7552 03-5679-7844 06-6301-7778
>>>> 03-3851-4141 03-5679-7848
>>>>
>>>> *More numbers may exist
>>>>
>>>> Resolution: Ignore calls from any of the numbers listed
>>> above and DO NOT
>>>> call back. Best practice is never to call a
>>> number that you
>>>> do not know.
>>>>
>>>> Status: The problem has been confirmed, but yet to be
>>> officially recognized
>>>> by mobile phone providers and is currently under investigation.
>>>
>>> --
>>> Thomas O'Dowd. - Nooping - http://nooper.com
>>> tom_at_nooper.com - Testing - http://nooper.co.jp/labs
>>>
>>> [ Need archives? How to unsubscribe?
>> http://www.appelsiini.net/keitai-l/ ]
>>
>> [ Need archives? How to unsubscribe?
>> http://www.appelsiini.net/keitai-l/ ]
>>
>
>
> __________________________________________________
> Do You Yahoo!?
> Yahoo! GeoCities - quick and easy web site hosting, just $8.95/month.
> http://geocities.yahoo.com/ps/info1
>
> [ Need archives? How to unsubscribe?
> http://www.appelsiini.net/keitai-l/ ]
>
[ Need archives? How to unsubscribe? http://www.appelsiini.net/keitai-l/ ]
Received on Sat Dec 1 07:30:54 2001