Wireshark-users: Re: [Wireshark-users] live data capture question

From: "AMEAUME ALAIN" <Alain.Ameaume@xxxxxxxxxxxxxxxxx>
Date: Fri, 29 Feb 2008 09:33:51 +0100

On Feb 28, 2008, at 3:05 PM, stephen galowski wrote:

> with regards to gsm and 3g protocols
>
> can a mobile phone with usb cable be connected to a computer , and be 
> able to track  them or would special equipment be needed to do this

2g & 3g protocols used to establish & transfer data & calls over radio
air interface are (dtap, bssmap, ranap) encapsulated in lapdm dedicated
protocol.

What you have to know is that these exchanges are protected against
"private life" violation : which means that 2g & 3g dedicated
securisation mechanisms could (that's not all the case used !) be
implemented by the mobile operator.
Ciphering keys associated with random numbers are used to cipher the
data, speech AND protocol itself (key kc in 2g or keys ck +ik in 3g).

The mobile to network interwork is so secured on the AIR Radio
interface.
Transmitting speech, video, audio or whatever else from a mobile
equipment to the network will used all the times this Radio AIR
interface : any other mobile station connectors (usb, serial, ..) are in
fact dedicated to used the station as a transmitter (function MT1) and
the computer connected on it as a "DTE" terminal only.

All the "call establishment" or "mobile location procedures" are done
between MT1 & the network (BTS or Node-B).
What you will capture on the usb port will be only the payload
transmitted (data, speech, video, audio, ...)

NOW, if you want to capture this payload, you need lawfull rights !
You can capture protocol messages using analyser equipments connected on
the network side ==> so you need operator rights!

Alain.