On Dec 27, 2012, at 11:23 , Sylvain Munaut wrote: >> how does an empty frame look like? all 2b 's? > > No there is some lapdm header, I don't remember exactly. > >> i can't see any in wireshark while using the mobile app. > > You wouldn't see them. They're added in layer1 when layer2+3 doesn't > have anything to say ... so they're not in wireshark.
Our presentation from 27C3 has more details: http://events.ccc.de/congress/2010/Fahrplan/attachments/1783_101228.27C3.GSM-Sniffing.Nohl_Munaut.pdf Slide 17 discusses some guessable frames, slide 19 states that one example of an empty frame is "03 03 01 2b ..." Cheers, -Karsten _______________________________________________ A51 mailing list [email protected] http://lists.lists.reflextor.com/cgi-bin/mailman/listinfo/a51
