[comp.dcom.telecom] Two Cellular Phones With the Same ESN

"John R. Covert 25-Jun-1991 0737" <covert@covert.enet.dec.com> (06/25/91)

Bob Lancelot at Motorola writes:

> I gave the CELLUSOFT SYSTEMS number a call this morning regarding
> two cellular phones with the same ESN.

> Talked with Mr. Hoser (sp?).  For $300 + $35 s&h he'll send you a
> device that allows you to program an ESN (specifically yours from
> another phone that you own) into a Novatel phone.

Yikes!

 From EIA/TIA-553, the standard that defines the AMPS protocol and
devices (and to which all manufacturers, service providers, repair
technicians, and cellular phone operators must comply or risk a visit
from the FCC):

2.3 Security and Identification

2.3.2. Serial Number

The serial number is a 32-bit binary number that uniquely identifies a
mobile station to any cellular system.  It must be factory-set and not
readily alterable in the field.  The circuitry that provides the
serial number must be isolated from fraudulent contact and tampering.
Attempts to change the serial number circuitry should render the
mobile station inoperative.

I'm really surprised that an employee of Motorola's Cellular Division
would publish information that would help people modify their
electronic serial numbers.  Supposedly the device sold by these guys
will only make the number the same as the number in some other phone
that you own, but even this is a violation of the standard -- and who
is going to make sure that dealers who market the device are going to
be honest.

It is specifically the fact that there are phones which apparently
don't break permanently when you try to do this and that there are
dealers out there selling devices to take advantage of poor phone
design that PREVENT ME FROM BEING ABLE TO DIRECT DIAL LONG DISTANCE
CALLS WHEN TRAVELLING.  Yes, I'm shouting, because I'm angry.

If you were to use this device, and were to accidentally leave both
phones powered on, believe me, your cellular carrier will be
interested in talking to you about why you are operating equipment in
violation of approved standards.


john

lancelot@uunet.uu.net> (06/26/91)

John R. Convert writes:

> I'm really surprised that an employee of Motorola's Cellular Division
> would publish information that would help people modify their
> electronic serial numbers.  Supposedly the device sold by these guys
> will only make the number the same as the number in some other phone
> that you own, but even this is a violation of the standard -- and who
> is going to make sure that dealers who market the device are going to
> be honest.

It was not my intent to imply endorsement of the fraudulent
modification of ESNs by posting the information received from
CELLUSOFT SYSTEMS.  It is partly due to the fact that I am employed by
Motorola Cellular that I have an interest in these devices and their
availability.

> It is specifically the fact that there are phones which apparently 
> don't break permanently when you try to do this and that there are
> dealers out there selling devices to take advantage of poor phone
> design that PREVENT ME FROM BEING ABLE TO DIRECT DIAL LONG DISTANCE
> CALLS WHEN TRAVELLING.  

Fraud is certainly a problem within the AMPS systems.  However, I
believe the main reason that you cannot direct dial long distance
calls from your cellular phone is due to the lack of interworking
among the operators and the lack of a national clearinghouse.  IS-41
is addressing this issue.  (Perhaps someone more knowledgeable in this
area can provide details for John.)