Hey Terje,

On Mon, Feb 29, 2016 at 12:46:30PM +0100, Terje Kristoffer Hybbestad Skow wrote:

Does this mailinglist also regard openGGSN?

Yes, the Osmocom community has adopted maintenance of OpenGGSN, even though it wasn't written "here".

If so do I have some questions. I have problem setting it up correctly.

To test the basic openggsn I used to do something like this:

sudo -s

LD_LIBRARY_PATH=/usr/local/lib ./git/openggsn/ggsn/ggsn -f -c ./localggsn.conf &

./git/openggsn/sgsnemu/sgsnemu --createif -l 127.0.0.1 -r 127.0.0.2

With localggsn.conf as

listen 127.0.0.2 net 127.0.0.0/24 pcodns1 8.8.8.8 logfile /tmp/foo

The above works on linux because it allows implicitly creating the 127.*.*.* interfaces. On other OSes, you'd have to create those first on one of your network interfaces.

See http://git.osmocom.org/openggsn/tree/examples/ggsn.conf for more config options.

I'd recommend to use wireshark to see what packets are transmitted back and forth, if you're not already doing that.

I've "recently" implemented GTPhub, which relays GTP, e.g. through a NAT. If that's of interest too, call again, and I can give you an example config for testing sgsnemu -> gtphub -> openggsn, too.

To actually relay data through the tunnel interface that is created, AFAIK you first need to send a Create PDP Context message to the GGSN. Maybe read http://git.osmocom.org/openbsc/tree/openbsc/tests/gtphub/gtphub_test.c For testing real data, I used an actual sysmoBTS with a "special" SIM card instead of sgsnemu, because here in the lab that was easier... :P

Hope to have helped :)

~Neels