Caller ID Spoofing in PSTN

[omara007]

Hey Folks

Anyone here knows the technology behind Caller ID Spoofing is done over Public Switching Telephone Network (Landline Telephone Network)?

 

[Dan Mills]

You can do interesting things with ISDN based connections, or completely wild things if you have access the your telecoms SS7 network (Sometimes this is actually available!).

ISDN, you can set the apparent caller ID, but the telecoms will still have the real data, SS7 you can basically do anything the telecom company can do.

Regards, Dan.

 

[omara007]

Thanks Dan. I indeed heard that with ISDN one can do caller ID spoofing. But what if I have just an analog landline telephone at home? .. can I still do spoofing? .. I heard about some techniques without much technical details like orange boxing .. and dialling some audible tones after the call is answered to fool the called party .. still, I don't have a clear vision of how such techniques work!

 

[betwixt]

The method would depend on the Telco in your country, there are several PSTN specifications for CID. In some countries a line polarity reversal is needed to alert the receipient equipment that a CID data block is imminent, in which case it cannot be done. Some countries use a specific carrier frequency or frequency pair (not the same as DTMF tones) to alert the recipient, for example 2130Hz and 2750Hz in my country and some used timed data windows between ringing voltage bursts.

I think they all use the similar FSK signalling protocols at 1200 bauds. My country uses 1 = 1300Hz and 0 = 2100Hz.

Brian.