Xref: utzoo alt.folklore.urban:3108 sci.electronics:13359
Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!mq!alan
From: alan@mq.UUCP (Alan H. Mintz)
Newsgroups: alt.folklore.urban,sci.electronics
Subject: Re: free calls?
Message-ID: <30@mq.UUCP>
Date: 5 Aug 90 20:55:53 GMT
References: <32457@cup.portal.com>
Followup-To: sci.electronics
Distribution: na
Organization: Micro-Quick Systems, Inc.
Lines: 34

In article <32457@cup.portal.com>, dbell@cup.portal.com (David J Bell) writes:
> OK: here's one to research. My son told us of a friend at work, whose
> father had picked up from am aquaintance at a major aerospace/electronics
> company, a replacment chip for some model of cellular phone. This 
> replacement chip (possibly a ROM or pROM) supposedly allows unlimited
> free calling.
> 
> Now, I can see a probable difficulty in *receiving* calls on the
> modified phone, as the unit ID may be what gets modified/trashed, but
> it would seem at least possible that unlimited *outgoing* calls could
> go through without being billed. For example, the ROM could ID the
> unit as a service rig, and billing would be to the carrier's overhead...

For most systems, ALL calls are billed to SOME account. I believe some 
switches may allow the existence of certain "Maintenance" numbers, but most
carriers choose not to use this. 

Each cellular phone has an ESN (Electronic Serial Number) and a MIN (Mobile
ID Number or Phone Number). The two must match the record in the switch in 
order for an incoming or outgoing call to be completed. These are usually
stored in two separate places in the phone. The ESN is usually somehow
affixed to the frame or buried or epoxied. The device that stores the MIN
is easily changeable. You would have to change both to allow what you are
talking about.

In any case, it is clearly unlawful to alter the ESN of a cellular phone!
This has been tried and proven in Federal Court under laws pertaining to
altering of serial number of electronic equipment (about three years ago,
in Florida I believe).
-- 
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