[A51] guesing frames

Karsten Nohl nohl at virginia.edu
Thu Dec 27 11:31:29 CET 2012


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




More information about the A51 mailing list