Cellular Network Infrastructure » Core Network (CN) » OsmoGGSN (former OpenGGSN)

h1. [[OpenGGSN]]

[[OpenGGSN]] is an implementation of the Gateway GPRS Support Node ("GGSN":http://en.wikipedia.org/wiki/GGSN) element in the GPRS core network.

[[OpenGGSN]] was developed in 2002 to 2004 by Mondru AB and was abandoned for some years before adopted by the Osmocom project around 2010.

h2. Source Code / git repository

The source code is maintained in the osmcoom git at http://git.osmocom.org/openggsn/

h2. Binary packages

OpenGGSN packages are created as part of the Osmocom nightly debian builds, see [[cellular-infrastructure:NightlyBuilds]]

h2. Support / mailing lists

Please direct any questions regarding use, configuration or development of OpenGGSN to the osmocom-net-gprs@lists.osmocom.org mailing list, to which you can subscribe at https://lists.osmocom.org/mailman/listinfo/osmocom-net-gprs

h2. Building OpenGGSN with kernel-gtp 

Ubuntu 16.10, kernel 4.8.0-30-generic is used. 

* Installing dependencies and build library @libgtpnl@

You can install those packages with:

<pre>

sudo apt install libtalloc-dev libpcsclite libmnl-dev

</pre>

Please follow instructions provided at [[https://osmocom.org/projects/cellular-infrastructure/wiki/Build_from_Source]] in order to install these library and projects:

Information about dependencies between Osmocom projects is given at the above link:

* libgtpnl

<pre>

  sudo make install

  sudo ldconfig

</pre>

* libosmocore 

* openggsn

<pre>

./configure --enable-gtp-linux

</pre>

Following message is shown at end of the command @ ./configure --enable-gtp-linux@ response:

<pre>

openggsn Configuration:

  GTP Linux kernel support:			yes

</pre>

This means that appropriate header files are available.

<pre>

sudo make install

sudo ldconfig

</pre> 

h2. Using OpenGGSN with kernel-gtp 

In order to find out whether gtp.ko module is available we can enter following command:

<pre>

find /lib/modules/`uname -r` -name gtp.ko

</pre>

In case of similar output:

<pre>

/lib/modules/4.8.0-28-generic/kernel/drivers/net/gtp.ko

</pre>

we can be sure that gtp.ko module is present.

with <pre>sudo modprobe gtp </pre> 

we are loading module gtp from kernel.

issuing command give us information about gtp:

@lsmod | grep gtp@

<pre>

gtp                    28672  0

udp_tunnel             16384  1 gtp

</pre>