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<br><br><div><div id="SkyDrivePlaceholder"></div><hr id="stopSpelling"><br><div dir="ltr">Hello everybody
<br>
<br>First of all, let me introduce myself. My name is Yann Moupinda and I'm
a student doing his Master thesis in the field of
<br>GSM technology. For my thesis, the company for which i'm working now,
bought a sysmoBTS from sysmocom. The
<br>sysmoBTS is configured as a stand alone GSM network in a box (NITB)
running the osmo-nitb and the osmo-bts programs.
<br>
<br>An important part of my thesis is to understand how the sysmoBTS works
and therefore I did some measurements with
<br>wireshark to analyse the data flow between the BTS,BSC and
MSC/HLR/VLR/EIR. This is also to see the main differences between a
sysmoBTS and a conventional GSM Network.
<br>
<br>I used the " tcpdump " - command on the loopback interface lo0 to
capture the data flow between the GSM components and then, the analysis
with wireshark shows me only the data flow between BTS and BSC. It's
possible to see such messages like LOCATION UPDATING REQUEST and
IDENTITY REQUEST wich are normally, transparently exchanged between
Mobile Station (MS) and the Network subsystem (MSC/HLR/VLR/EIR). All
these messages are always addressed to, or from the same BSC TCP-port
3003. So i can not see what happens behind this port (behind BSC).
<br>In order to get the communication between BSC and MSC, i decided to
have a deeper look on the logging messages of the sysmoBTS. Even there,
i cannot recognize how the data transmission between BSC and MSC works.
<br>
<br>Does anyone know how to get this information? Any guidance would be
appreciated.
<br>
<br>I have included one .pcap file and a text file of the logging messages
taken while i powered on the mobile phone.
<br>
<br>Best regards,
<br>Yann.
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