Stun Module

Razvan Pistolea

   <razvy000@yahoo.com>

Edited by

Razvan Pistolea

   <razvy000@yahoo.com>

   Copyright © 2009 Voice Sistem SRL
   Revision History
   Revision $Revision:$ $Date$
     __________________________________________________________

   Table of Contents

   1. Admin Guide

        1.1. Overview

              1.1.1. The idea
              1.1.2. Basic Operation
              1.1.3. Supported STUN Attributes

        1.2. Dependencies

              1.2.1. OpenSIPS Modules
              1.2.2. External Libraries or Applications

        1.3. Exported Parameters

              1.3.1. primary_ip (str)
              1.3.2. primary_port (str)
              1.3.3. alternate_ip (str)
              1.3.4. alternate_port (str)

        1.4. Exported MI Functions

   List of Examples

   1.1. Set primary_ip parameter
   1.2. Set primary_port parameter
   1.3. Set alternate_ip parameter
   1.4. Set alternate_port parameter

Chapter 1. Admin Guide

1.1. Overview

1.1.1.  The idea

   A stun server working with the same port as SIP (5060) in order
   to gain accurate information. The benefit would be an exact
   external address in the case of NATs translating differently
   when given different destination ports. The server may also
   advertise different network addresses than the ones it is
   actually listening on.

1.1.2.  Basic Operation

   The stun server will use 4 sockets:
     * socket1 = ip1 : port1
     * socket2 = ip1 : port2
     * socket3 = ip2 : port1
     * socket4 = ip2 : port2

   The sockets come from existing SIP sockets or are created.

   Socket1 must allways be a SIP UDP listener from OpenSIPS.

   The server will create a separate process. This process will
   listen for data on created sockets. The server will register a
   callback function to SIP. This function is called when a
   specific (stun)header is found.

1.1.3.  Supported STUN Attributes

   This stun implements RFC3489 (and XOR_MAPPED_ADDRESS from
   RFC5389)

     * MAPPED_ADDRESS
     * RESPONSE_ADDRESS
     * CHANGE_REQUEST
     * SOURCE_ADDRESS
     * CHANGED_ADDRESS
     * ERROR_CODE
     * UNKNOWN_ATTRIBUTES
     * REFLECTED_FROM
     * XOR_MAPPED_ADDRESS

   Not supported attributes:

     * USERNAME
     * PASSWORD
     * MESSAGE_INTEGRITY

   and associated ERROR_CODEs

1.2. Dependencies

1.2.1. OpenSIPS Modules

   The following modules must be loaded before this module:

   None.

1.2.2. External Libraries or Applications

   The following libraries or applications must be installed
   before running OpenSIPS with this module loaded:
     * None.

1.3. Exported Parameters

1.3.1.  primary_ip (str)

   The IP of an interface which is configured as an UDP SIP
   listener in OpenSIPS. This is a mandatory parameter.

   Syntax: "ip [/ advertised_ip]

   By default, the primary_ip and the advertised primary_ip will
   be identical. This may be changed with an optional "/
   xxx.xxx.xxx.xxx" string.

   Example 1.1. Set primary_ip parameter
...
modparam("stun", "primary_ip", "192.168.0.100")

# Example of a STUN server within OpenSIPS which is behind NAT
modparam("stun", "primary_ip", "192.168.0.100 / 64.50.46.78")
...

1.3.2.  primary_port (str)

   The port configured (together with the primary_ip) as an UDP
   SIP listener in OpenSIPS. The default value is 5060.

   Syntax: "port [/ advertised_port]

   By default, the primary_port and the advertised primary_port
   will be identical. This may be changed with an optional "/
   adv_port" string.

   Example 1.2. Set primary_port parameter
...
modparam("stun", "primary_port", "5060")

# Listening on a primary port, but advertising a different one
modparam("stun", "primary_port", "5060 / 5062")
...

1.3.3.  alternate_ip (str)

   Another IP from another interface. This is a mandatory
   parameter.

   Syntax: "ip [/ advertised_ip]

   By default, the alternate_ip and the advertised alternate_ip
   will be identical. This may be changed with an optional "/
   xxx.xxx.xxx.xxx" string.

   Example 1.3. Set alternate_ip parameter
...
modparam("stun","alternate_ip","11.22.33.44")

# Example of a STUN server within OpenSIPS which is behind NAT
modparam("stun", "alternate_ip", "192.168.0.100 / 64.78.46.50")
...

1.3.4.  alternate_port (str)

   The port used by the STUN server for the second interface. The
   default value is 3478 (default STUN port).

   Syntax: "port [/ advertised_port]

   By default, the alternate_port and the advertised
   alternate_port will be identical. This may be changed with an
   optional "/ adv_port" string.

   Example 1.4. Set alternate_port parameter
...
modparam("stun","alternate_port","3479")

# Listening on an alternate port, but advertising a different one
modparam("stun", "alternate_port", "5060 / 5062")
...

1.4. Exported MI Functions
