On Apr 13, 2019, at 12:35 AM, Harald Welte <laforge(a)gnumonks.org> wrote:
the "physical link info" is present in
GSMTAP, but the granularity of
GSMTAP frames is not user-IP frames, but "MAC blocks". So your user IP
frame might not be visible as it's still compressed, encrypted,
fragmented, etc.
The granularity of Ethernet frames is not user IP frames, but Ethernet datagrams, so you
user IP frame might not be visible as it's fragmented (the fragments might still be IP
datagrams, but they would have to be reassembled - which Wireshark, for example, does, for
those people still doing NFS-over-UDP :-)).
"Encrypted" may not apply there, but it *does* apply for 802.11 frames on a
protected network (which Wireshark can decrypt, if you have 1) the network password for
WEP or WPA-Personal and 2) the EAPOL handshake for WPA-Personal).