Ethereal-dev: [Ethereal-dev] sample file for GSM frames

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Date: Wed, 3 Aug 2005 13:45:41 +0200

Hi
I am trying to analyse some GSM layer-2 frames that I extracted from my mobile phone.
The problem is that they don't have the right header.
If I understand correctly, Ethereal needs the frame to be inside TCP-IP encapsulation, probably also inside something called MCU2 or similar.
But this doesn't apply to GSM, so I would need someone to embed my GSM inside a frame that Ethereal can understand.

I suppose the developpers for the gsm_map dissector have such examples, so if you can send me an example file, it will be perfect for me.

Thanks
Francisco

for example, this is one of my frames:

25 06 21 00 05 f4 64 11 77 9e 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b

25  001001--  Pseudo length : 9
    ------01  Flag
06  0-------  direction from      : originating site
    -000----  TransactionID       : 0
    ----0110  Protocol Discrim.   : radio resource management messages

21  00100001  MESSAGE TYPE        : PAGING REQUEST TYPE 1

00  ----00--  spare bits          : 0
    ------00  Page Mode           : Normal paging
    --00----  Channel Needed      : (first) Any Channel
    00------  Channel Needed      : (second) Any Channel

: Mobile Identity 1
05  00000101  length of Mob.ident.: 5                
f4  1111----  Identity Digit 1    : hex value = f, if  TMSI/P-TMSI
    ----0---  No. of ID digits    : even
    -----100  Type of identity    : TMSI/P-TMSI
64  01100100  Identity Digit 2,3  : take hex value
11  00010001  Identity Digit 4,5  : take hex value                  
77  01110111  Identity Digit 6,7  : take hex value                          
9e  10011110  Identity Digit 8,9  : take hex value