OpenGGSN was developed in 2002 to 2004 by Mondru AB and was abandoned for some years before adopted by the Osmocom project around 2010.
Source Code / git repository¶
The source code is maintained in the osmcoom git at http://git.osmocom.org/openggsn/
OpenGGSN packages are created as part of the Osmocom nightly debian builds, see NightlyBuilds
Support / mailing lists¶
Please direct any questions regarding use, configuration or development of OpenGGSN to the firstname.lastname@example.org mailing list, to which you can subscribe at https://lists.osmocom.org/mailman/listinfo/osmocom-net-gprs
Building OpenGGSN with kernel which has GTP-U support¶
At the time of writing (2017-01-09) of this wiki, below listed distributions have support of GTP kernels :
- Debian 4.9.1-1~exp1 - Debian's latest experimental build
- Ubuntu 16.10 kernel 4.8
- OpenSUSE Tumbleweed (stable) 4.8 (.12)
- Fedora 25 kernel 4.8
Following two Debian kernels do not activate GTP kernel module during build: 4.8.0 and 4.9.0.
It is expected that complete openbsc project and related dependencies are pre-installed.
Check if package
libc-ares-dev is installed and if not please add it.
Ubuntu 16.10, kernel 4.8.0-30-generic is used.
- Installing dependencies and build library
You can install those packages with:
sudo apt install libtalloc-dev libpcsclite libmnl-dev
Please follow instructions provided at Build from source in order to install following library and projects :
Information about dependencies between Osmocom projects is given at the above link:
sudo make install sudo ldconfig
./configure --enable-gtp-linux make sudo make install sudo ldconfig
Following message is shown at end of the command:
openggsn Configuration: GTP Linux kernel support: yes
This means that appropriate header files are available.
Using OpenGGSN with kernel which has GTP-U support¶
In order to find out whether gtp.ko module is available we can enter following command:
find /lib/modules/`uname -r` -name gtp.ko
Output below shows that gtp.ko module is present:
We are loading module gtp from kernel issuing command:
sudo modprobe gtp
when you enter:
lsmod | grep gtp
then more information about gtp and related udp tunnel can be obtained:
gtp 28672 0 udp_tunnel 16384 1 gtp
Some helpful tools are available in:
you can get more details about gtp-tunnel, entering command from the OpenGGSN shell:
sudo ./gtp-tunnel list
Output will be similar to:
version 1 tei 1/0 ms_addr 192.168.0.2 sgsn_addr 127.0.0.2
Furthermore we can use:
sudo starce ggsn --gtp-linux -c ggsn.conf -f -dto determine if Ubuntu 16.10, kernel 4.8.0-30 is in use.
Next two cases shall be considered as an indication whether gtp kernel module is active:
- If gtp kernel module is active then we can see the strace output just when PDP context activation or deactivation is done.
- If gtp kernel module is not active then we can see the strace output constantly running on the screen.
Note: OpenGGSN is started by:
sudo ggsn --gtp-linux -c ggsn.conf -f -d
-d option is useful for debugging purposes.
Related output should be similar to the one shown below:
conf: ggsn.conf fg: 1 debug: 1 qos: 0x0b921f apn: internet net: 192.168.0.0/24 pidfile: /var/run/ggsn.pid statedir: /var/lib/ggsn/ gtp_linux: 1 timelimit: 0 cmdline_parser_configfile listen: 127.0.0.1 conf: ggsn.conf fg: 1 debug: 1 qos: 0x0b921f apn: internet net: 192.168.0.0/24 pidfile: /var/run/ggsn.pid statedir: /var/lib/ggsn/ gtp-linux: 1 timelimit: 0 <000c> gtp.c:701 GTP: gtp_newgsn() started <0002> gtp-kernel.c:123 Using the GTP kernel mode (genl ID is 27) <0002> gtp-kernel.c:156 GTP kernel configured <000b> control_if.c:693 CTRL at 127.0.0.1 4257
osmosgsn can be started with:
sudo osmo-sgsn -c sgsn.cfg
- d option is also available ins osmo-sgsn command.
Additional information related to setup of openbsc and GPRS setup is available OpenBSC GPRS
For clarity purposes configuration files of openbsc, OpenGGSN, osmosgsn and sysmoBTS are added.