ggsn(8)

NAME

ggsn - Gateway GPRS Support Node.

SYNOPSIS

ggsn --help
ggsn --version
ggsn [ --fg ] [ --debug ] [ --conf file ] [ --pidfile file
]  [  --statedir  file ] [ --listen host ] [ --net net ] [ --ipup
script ] [ --ipdown script ] [ --dynip net ] [ --statip net  ]  [
--pcodns1 host ] [ --pcodns2 host ] [ --timelimit seconds ]

DESCRIPTION

ggsn is part of the OpenGGSN project, and implements a

Gateway GPRS Support Node. It is used by mobile operators as the

interface between the Internet and the rest of the mobile network

infrastructure.

The GPRS functionality and protocols has been standardised

by the Third Generation Partnership Project (3GPP). According to

the 3GPP specifications a GGSN has two interfaces: The Gn/Gp in

terface and the Gi interface.

The Gn/Gp interface can be seen as the downlink interface

of the GGSN. It is used for communicating with the Serving GPRS

Support Node (SGSN) which again interfaces to the radio access

network. The Gn/Gp interface uses the GPRS tunneling protocol

(GTP). User data packets (typically IP packets) are tunneled over

GTP, which again uses UDP over IP.

The other interface can be thought of as the uplink inter

face, and interfaces the GGSN to an external data network. Gi is

most often an interface to the Internet. ggsn uses the TUN/TAP

driver for the Gi interface. A tun network interface is estab

lished when the ggsn is started.

ggsn will accept incoming connections from mobile stations

through the radio access network and the SGSN. When a connection

request is received the ggsn will allocate a dynamic IP address

for the mobile station, and allow the mobile station to access

the Gi interface. Connections are terminated by either the mobile

station or the SGSN. Runtime errors are reported using the

syslogd (8) facility.

Typically ggsn will be deployed with two Ethernet inter

faces. One for the Gn/Gp interface, and one for the Gi interface.

Policy routing and firewall rules should be used in order to sep

arate Gi traffic from Gn/Gp traffic.

OPTIONS

--help Print help and exit.

--version

Print version and exit.

--fg Run in foreground (default = off)

--debug

Run in debug mode (default = off)

--conf file

Read configuration file (default = /etc/ggsn.conf)

where each line corresponds to one command line option, but with

the leading '--' removed. Command line options override the op

tions given in the configuration file.

--pidfile file

Filename of process id file (default =

/var/run/ggsn.pid)

--statedir path

path to directory of nonvolatile data (default =

/var/lib/ggsn/)

--listen host

Local interface IP address to use for the Gn/Gp in

terface. This option must be specified. For security issues it is

not possible to use INADDR_ANY.

--net net

Network address of the Gi interface (default =

192.168.0.0/24). The network address is set during initialisation

when ggsn establishes a tun device for the Gi interface.

--ipup script

Script executed after the Gi tun network interface

has been brought up. Executed with the following parameters:

<devicename> <ip address>

--ipdown script

Script executed after the Gi tun network interface

has been taken down. Executed with the following parameters:

<devicename> <ip address>

--dynip net

Dynamic IP address pool. Specifies a pool of dynam

ic IP addresses. If this option is omitted the network address

specified by the --net option is used for dynamic IP address al

location.

--pcodns1 host

PCO DNS Server 1 (default = 0.0.0.0). PCO stands

for Protocol Configuration options, and is part of the GPRS pro

tocols. It is used to inform the mobile station about the DNS ad

dress to use for host name resolution.

--pcodns2 host

PCO DNS Server 2 (default = 0.0.0.0). PCO stands

for Protocol Configuration options, and is part of the GPRS pro

tocols. It is used to inform the mobile station about the DNS ad

dress to use for host name resolution.

--timelimit seconds

Exit after seconds. Used for debugging.

FILES

/etc/ggsn.conf

The configuration file for ggsn.

/var/run/ggsn.pid

Process ID file.

/var/lib/ggsn

Directory holding nonvolatile data.

BUGS

Report all bugs to the OpenGGSN bug tracking list at

http://sourceforge.net/projects/ggsn/

ggsn has very limited management support. Currently both

SNMP as well as billing mechanisms are missing.

SEE ALSO

sgsnemu(8), syslogd(8)

NOTES

Besides the long options documented in this man page ggsn

also accepts a number of short options with the same functionali

ty. Use ggsn --help for a full list of all the available options.

The TUN/TAP driver is required for proper operation of

ggsn. For linux kernels later than 2.4.7 the TUN/TAP driver is

included in the kernel, but typically needs to be loaded manually

with modprobe tun. For automatic loading the line alias

char-major-10-200 tun can be added to /etc/modules.conf. For

other platforms see http://vtun.sourceforge.net/tun/ for informa

tion on how to install and configure the tun driver.

ggsn uses the GPRS Tunneling Protocol (GTP) as specified

by the Third Generation Partnership Project (3GPP). 3GPP proto

cols specifications can be found at http://www.3gpp.org

COPYRIGHT

Copyright (C) 2002, 2003 by Mondru AB.

The contents of this file may be used under the terms of

the GNU General Public License Version 2, provided that the above

copyright notice and this permission notice is included in all

copies or substantial portions of the software.

AUTHORS

Jens Jakobsen <jj@openggsn.org>

July 2003

ggsn(8)