Hi
I have a question regarding the handshake signals in V.92 which I need
to detect. My objective is to detect modem handshake signals without
the need to distinguish between them.

The Qc1X are easy to detect as they begin with 10 one at V.21
modulation.
What about:
QC2a
QCA2a
QC2d
QCA2d?

The ITU recommendation says these signals use the structure defined in
clause 7/V.8 bis and the information field structure defined in clause
8/V.8 bis.
Does it mean that they are all preceded by the message preamble
defined in V.8 bis as well?

Do you know a better source of info than the ITU recs?

thanx

Momo