ASDL uses frequencys higher (why you dont hear it, check out the ear frequency response, google) than that of the standard method of communication on a PSTN, your modem connects to a DSLAM (go google it), this splits POTS (go google it) and adsl parts of your communcation, so this obviously has some knowledge of phone numbers to route them.

The traffic only becomes TCP/IP after it has passed the ATM network and Home Gateway (these might just be specific names to BT), this traffic is then Transmitted to the ISP.

So id imagine then that the DSLAM translates your phone number into a routing code of some description and that this is passed to the home gateway where the translation occurs, to TCP/IP

So unless you have access to the hardware, like BT, I think you'd find it hard to recover this, I believe that even the ISP would have to go to BT for this information unless they hold it on registration. Im not sure that even the police have ready access to this information, without the assistance of BT - besides legislation like the RIPA.

Sorry to use BT (british telecom, or , but thats all I know.


i2c