Re: OpenGGSN

On Tue, Mar 01, 2016 at 11:12:01AM +0100, Terje Kristoffer Hybbestad Skow wrote: 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 ways simulate 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_129… 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(a)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