ProxyDB.com Team wrote:
I don't know if I post to the right list but considering that I have
a problem related to sniffing I'll post it here.
It's not sniffing at the level Ethereal does - Ethereal assumes some
hardware is already doing the low-level signal processing and, in fact,
also assumes that some other hardware or firmware or driver code is
doing the link-layer packet framing - but I'll try to answer it anyway.
Is there any way, to convert the audio from the phone line back to
the original, bytes sniffing from the phone line directly and not from the
modem?
That would probably involve a significant amount of signal processing -
equivalent to what the modem is doing; modern modems, as far as I know,
include digital signal processors to convert the analog signal into a
sequence of "symbols" (each of which I think corresponds to multiple
bits), and there's also, I think, an error-correcting protocol used atop
the raw sequence of symbols or bits.
I don't know of any code to do that other than the code in a modem's
firmware or in a WinModem's driver - perhaps some Linux or BSD WinModem
driver is open source. You'd be on your own figuring out what hardware
and software you need to tap the line in that fashion (assuming you can
tap into the middle of a conversation - you might need to see the
initial negotiation sequence between the two modems to be able to decode
the analog signal).
