sgsnemu - Serving GPRS Support Node Emulator
] [ --conf file
] [ --statedir file
] [ --listen host
] [ --contexts num
] [ --gtpversion version
] [ --selmode selmode
] [ --nsapi nsapi
] [ --qos qos
] [ --uid uid
] [ --createif
] [ --net net
] [ --ipup script
] [ --ipdown
] [ --pinghost host
] [ --pingrate num
] [ --pingsize num
] [ --pingcount num
is part of the OpenGGSN
project, and implements a Serving
GPRS Support Node (SGSN) emulator. It can be used for testing Gateway GPRS
Support Nodes (GGSNs), GPRS core networks as well as GPRS roaming connections.
The GPRS functionality and protocols has been standardised by the Third
Generation Partnership Project (3GPP). According to the 3GPP specifications an
SGSN has several interfaces. sgsnemu
implements the Gn/Gp interface
which is used towards GGSNs.
The Gn/Gp interface can be seen as the uplink interface of the SGSN. It is used
for communicating with a GGSN which is typically connected to the Internet.
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.
will establish a number of connections to the GGSN. An internal
ping facility will transmit ping requests through the established connections.
Alternatively a local network interface can be created. In this case
will forward packets between the local network interface and
the established connections on the Gn/Gp interface.
uses the TUN/TAP driver
for the local interface. A tun
network interface is established for each connection established to the GGSN.
Runtime errors are reported using the Osmocom logging framework.
- Print help and exit.
- Print version and exit.
- Run in debug mode (default = off)
- --conf file
- Read configuration file where each line corresponds
to one command line option, but with the leading '--' removed. Command
line options override the options given in the configuration file.
- --pidfile file
- Filename of process id file (default =
- --statedir path
- path to directory of nonvolatile data (default = ./)
- --dns host
- DNS server to use for APN lookups. If omitted the default
system DNS configuration will be used.
- --listen host
- Local interface IP address to use for the Gn/Gp interface.
If omitted sgsnemu will listen to any IP address.
- --remote host
- GGSN host to connect to. If DNS is setup correctly
it should be possible to specify the access point name (APN) as the remote
- --contexts num
- Number of contexts to establish. (default = 1). For
multiple contexts the the first context is established using imsi + 0 and
msisdn + 0. The second context is established using imsi + 1 and msisdn +
1. The third....
- --timelimit seconds
- Exit sgsnemu after seconds. When using the
ping facility sgsnemu will also exit after --pingcount
packets has been transmitted.
- --gtpversion version
- version of GTP to use when establishing a context
(default = 1). If not able to establish a GTPv1 context sgsnemu will fall
back to using GTPv0.
- --apn apn
- apn to use when connecting to the GGSN (default =
internet). APN is an abbreviation of Access Point Name.
- --selmode selmode
- Selection mode to use when connecting to the GGSN (default
= 0x01). The encoding of the selection mode is as follows: 0: MS or
network provided APN, subscribed verified, 1: MS provided APN,
subscription not verified, 2: Network provided APN, subscription not
- --imsi imsi
- imsi to use when connecting to the GGSN (default =
240010123456789). IMSI is an abbreviation of International Mobile
Subscriber Identity. Must be exactly 15 digits. See the contexts
option for the the use of the imsi option with multiple contexts.
- --nsapi nsapi
- nsapi to use when connecting to the GGSN (default =
0). Must be between 0 and 15.
- --msisdn msisdn
- msisdn to use when connecting to the GGSN (default =
46702123456). MSISDN is an abbreviation of International Mobile Integrated
Services Digital Network. Effectly a phone number in international format
without the leading 00 or 011. See the contexts option for the the
use of the msisdn option with multiple contexts.
- --qos qos
- qos to use when connecting to the GGSN (default =
0x0b921f). QoS is an abbreviation of Quality of Service. See 3GPP
specification 09.60 for the format of this string.
- --charging charging
- Charging characteristics to use when connecting to the GGSN
(default = 0x0800). 0x0800 = Normal, 0x0400 = Prepaid, 0x0200 = Flat rate,
0x0100 = Hot billing. See 3GPP specification 32.015 for the format of this
- --uid uid
- User ID to send to GGSN as protocol configuration option.
- --pwd pws
- Password to send to GGSN as protocol configuration option.
- Create a local tun interface. This interface will be used
for forwarding packets to and from the Gn/Gp interface. Use with caution
as the Gn/Gp interface is normally be routed to the Internet by the GGSN.
Only one interface will be created, even if several contexts are
established. The interface will be given an IP address for each
established context, or the address can be specified with the net
- --net net
- Network address of the local interface. The net
option is only valid when the createif option is used. The
net option is given in cidr format (net/mask bits). If the
net option omitted an IP address is allocated for each context
- Create a defaultroute to the local tun interface.
- --ipup script
- Script executed after the tun network interface has been
brought up. Executed with the following parameters: <devicename>
- --ipdown script
- Script executed after the tun network interface has been
taken down. Executed with the following parameters: <devicename>
- --pinghost host
- Ping host through the Gn/GP interface. Ping
statistics are reported much like done by the original ping program. Use
this facility for performance test of GGSNs.
- --pingrate num
- Number of ping requests per second (default = 1)
- --pingsize num
- The size of each ping requests in octets (default = 56)
- --pingcount num
- Number of ping requests to send (default = 0). A value of 0
(zero) indicates infinite.
- Do not print information for each packet received (default
= off). Is quite useful for high pingrates.
The configuration file for
Process ID file.
Directory holding nonvolatile data.
Report all bugs to the OpenGGSN bug tracking list at
Besides the long options documented in this man page sgsnemu
a number of short options with the same functionality. Use sgsnemu
for a full list of all the available options.
The TUN/TAP driver is required for proper operation of sgsnemu.
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.
loading the line alias char-major-10-200 tun
can be added to
For other platforms see
for information on how to install and
configure the tun driver.
uses the GPRS Tunneling Protocol (GTP) as specified by the Third
Generation Partnership Project (3GPP). 3GPP protocols specifications can be
found at http://www.3gpp.org
Copyright (C) 2002, 2003, 2004 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
Jens Jakobsen <email@example.com>