17 Jun
2009
17 Jun
'09
1:11 a.m.
On Tue, Jun 16, 2009 at 03:10:12PM +0200, Nordin wrote:
Hello guys,
I was reading the nanoBTS product description and found support for
"Network Listen" feature to monitor and decode GSM base stations. Is
that an ip.access specific protocol? If so, does anyone has the ability
to revers engineer this particular function. That would be really great!
The network listen feature is implemented by means of GSM 12.21 "EXECUTE TEST"
methods. So the activation/initiation of the network listen mode follows
the framework as set forth by 12.21, but the actual parameters as well
as the test results are vendor-specific attributes.
As far as I have noted, if you put the BTS in this mode it ceases to work
as normal BTS, so you cannot do that while you're actually using it
productively.
I've attached a pcap protocol trace of some old recorded network listen action.
Maybe this helps you to discover and document the details.
--
- Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/
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