This is merely a historical archive of years 2008-2021, before the migration to mailman3.
A maintained and still updated list archive can be found at https://lists.osmocom.org/hyperkitty/list/osmocom-net-gprs@lists.osmocom.org/.
Terje Kristoffer Hybbestad Skow terjeks at stud.ntnu.noThank you very much!! I will have some work getting through this, but I recon I'll have some more questions later. Again thank you 2016-03-01 12:39 GMT+01:00 Neels Hofmeyr <nhofmeyr at sysmocom.de>: > On Tue, Mar 01, 2016 at 11:12:01AM +0100, Terje Kristoffer Hybbestad Skow > wrote: > > The "logfile /tmp/foo" did gave an error message saying "unrecognized > > option". > > It seems the logfile option was added on 2014-03-23 with commit > 9c0ff4fafe4276396125a52c89d36967566fe08c. It may make sense if you build > your osmocom stack from the git sources to benefit from the latest fixes. > > See http://git.osmocom.org, specifically you'd probably want to clone and > build > > git://git.osmocom.org/libosmocore > git://git.osmocom.org/openggsn > > The build steps being for example > > autoreconf -fi > ./configure > make > sudo make install > > > > I'm going to look at DNS packets going through a GGSN to try and find > ways > > to detect DNS tunnels, do you have any recommendations how to do this? > > I do not have the time or resources to use real UE's so I hope to > simulate > > it on a computer using VMs or something like that. > > > I have looked at this: http://openbsc.osmocom.org/trac/wiki/OpenBSC_GPRS > as > > The BTS is for communicating with a phone over the air interface. Abis and > osmo-nitb are used for voice calls only. The SGSN is needed for real > networks, > you should be fine with the sgsnemu. So all you need is sgsnemu and > openggsn. > > You want to figure out how to use the sgsnemu, starting with a route into > the > tunnel device that sgsnemu opens up. So you need to look at the 'ip route' > commands (if you're on linux). I guess you won't need VMs; granted, it > might > make it easier to avoid circular routes (to IP addresses that should only > be > seen on the GGSN side), but certainly not a necessary prerequisite. > > I tried to ping through the sgsnemu tunnel once but saw, as I mentioned, > that > the GGSN thwarts GTP messages without a proper context being created > first. It > shouldn't be too hard, but I haven't investigated further. So you'd want to > understand the GTP Ctrl & User messages to setup a PGP context (TEIs and > stuff), and figure out how sgsnemu might make your life easier in that > regard. > You probably want to read ETSI 29.060 to figure out GTP: > > http://www.etsi.org/deliver/etsi_ts/129000_129099/129060/03.19.00_60/ts_129060v031900p.pdf > You may find attached pcap file interesting (open in wireshark and note > that > the DNS queries are transmitted over GTP between SGSN and GGSN even though > wireshark tends to show only the DNS and src/dest enclosed in the GTP). > And again, you may look at > http://git.osmocom.org/openbsc/tree/openbsc/tests/gtphub/gtphub_test.c > about simplistic code examples of composing a PGP context conversation. > > If you'd like any more answers to questions you didn't ask ;) > just give us a shout... > > ~Neels > > -- > - Neels Hofmeyr <nhofmeyr at sysmocom.de> http://www.sysmocom.de/ > ======================================================================= > * sysmocom - systems for mobile communications GmbH > * Alt-Moabit 93 > * 10559 Berlin, Germany > * Sitz / Registered office: Berlin, HRB 134158 B > * Geschäftsführer / Managing Directors: Holger Freyther, Harald Welte > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.osmocom.org/pipermail/osmocom-net-gprs/attachments/20160301/007077bf/attachment.htm>