WiresharkIntegration » History » Version 7
Anonymous, 02/19/2016 10:49 PM
Requires >1.4.0 to have GSMTAP build in.
1 | 1 | laforge | = Wireshark integration = |
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3 | 5 | laforge | [http://www.wireshark.org/ wireshark] is a popular Free Software / Open Source protocol analyzer. Among many |
4 | other protocols, it includes dissectors for the GSM Layer 2 (TS 04.06 / LAPDm) and 3 (TS 04.8 04.08 / RR,MM,CC). |
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5 | 1 | laforge | |
6 | 4 | laforge | There also is a [wiki:GSMTAP] protocol dissector in recent wireshark versions, which allows |
7 | real-time capture and decode of GSM protocol messages encapsulated in a GSMTAP (pseudo-header, |
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8 | which is in turn encapsulated in UDP and IP). |
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9 | 1 | laforge | |
10 | 7 | laforge | So if you have a wireshark version with [wiki:GSMTAP] support (>1.4.0), you can have real-time decode and |
11 | 6 | tsaitgaist | trace of GSM protocol messages. You can also [wiki:wireshark compile wireshark] yourself. |
12 | 1 | laforge | |
13 | 4 | laforge | The OsmocomBB [wiki:layer23] program sends [wiki:GSMTAP] packets to the localhost (127.0.0.1) address |
14 | of the loopback interface (lo). Please note that the wireshark program is doing passive capture, |
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15 | i.e. if nothing is listening on the [wiki:GSMTAP] UDP port (4729), then you will see ICMP port unreachable |
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16 | messages in addition to the GSMTAP messages. There are two suggested solutions to this: |
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17 | * Change the IP address to a multicast group like 224.0.0.1 (instead of 127.0.0.1) |
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18 | * Run some program that simply opens the UDP port and discards its content, e.g. using {{{{nc -u -l -p 4729 > /dev/null}}} |
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19 | 2 | laforge | |
20 | == Screenshot == |
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21 | |||
22 | [[Image(gsmtap-wireshark.png, 66%)]] |