Stun Module
     __________________________________________________________

   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)
              1.3.5. use_listeners_as_primary (int)

   2. Contributors

        2.1. By Commit Statistics
        2.2. By Commit Activity

   3. Documentation

        3.1. Contributors

   List of Tables

   2.1. Top contributors by DevScore^(1), authored commits^(2) and
          lines added/removed^(3)

   2.2. Most recently active contributors^(1) to this module

   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
   1.5. Set use_listeners_as_primary 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

   where ip1 / port1 represent an UDP SIP listener and ip2 / port2
   are configured via the alternate_ip and alternate_port
   parameters.

   The sockets come from existing SIP sockets or are created.

   Socket1 must allways be a SIP UDP listener from OpenSIPS.

   If use_listeners_as_primary is enabled the STUN server will
   actually use multiple sets of sockets obtained from the IP/port
   combinations described above, each set corresponding to 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, unless
   use_listeners_as_primary is enabled.

   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.

   If use_listeners_as_primary is enabled, the alternate IP must
   be either:
     * an IP from an existing UDP SIP listener configured in
       OpenSIPS, but one that is different from all the other UPD
       listeners;
     * an IP that is different from the UDP SIP listeners
       configured in OpenSIPS.

   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).

   If use_listeners_as_primary is enabled, the alternate port must
   be either:
     * a port from an existing UDP SIP listener configured in
       OpenSIPS, but one that is different from all the other UPD
       listeners;
     * a port that is different from the UDP SIP listeners
       configured in OpenSIPS.

   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")
...

1.3.5.  use_listeners_as_primary (int)

   Setting this parameter to 1 will allow all configured UDP SIP
   listeners to be automatically used as "primary" STUN sockets.

   The primary_ip and primary_port parameters will be ignored when
   this behavior is enabled.

   The default value is 0 (disabled).

   Example 1.5. Set use_listeners_as_primary parameter
...
modparam("stun","use_listeners_as_primary",1)
...

Chapter 2. Contributors

2.1. By Commit Statistics

   Table 2.1. Top contributors by DevScore^(1), authored
   commits^(2) and lines added/removed^(3)
     Name DevScore Commits Lines ++ Lines --
   1. Razvan Pistolea 20 3 1891 19
   2. Bogdan-Andrei Iancu (@bogdan-iancu) 18 13 137 128
   3. Liviu Chircu (@liviuchircu) 17 12 259 117
   4. Razvan Crainea (@razvancrainea) 14 12 27 20
   5. Vlad Paiu (@vladpaiu) 7 5 25 4
   6. Bernard 7 1 391 75
   7. Peter Lemenkov (@lemenkov) 3 1 1 1
   8. Vlad Patrascu (@rvlad-patrascu) 2 1 1 0

   (1) DevScore = author_commits + author_lines_added /
   (project_lines_added / project_commits) + author_lines_deleted
   / (project_lines_deleted / project_commits)

   (2) including any documentation-related commits, excluding
   merge commits. Regarding imported patches/code, we do our best
   to count the work on behalf of the proper owner, as per the
   "fix_authors" and "mod_renames" arrays in
   opensips/doc/build-contrib.sh. If you identify any
   patches/commits which do not get properly attributed to you,
   please submit a pull request which extends "fix_authors" and/or
   "mod_renames".

   (3) ignoring whitespace edits, renamed files and auto-generated
   files

2.2. By Commit Activity

   Table 2.2. Most recently active contributors^(1) to this module
                     Name                   Commit Activity
   1. Bernard                             Oct 2021 - Oct 2021
   2. Razvan Crainea (@razvancrainea)     Oct 2011 - Sep 2019
   3. Vlad Paiu (@vladpaiu)               Sep 2011 - Aug 2019
   4. Bogdan-Andrei Iancu (@bogdan-iancu) Sep 2009 - Apr 2019
   5. Liviu Chircu (@liviuchircu)         Mar 2014 - Nov 2018
   6. Peter Lemenkov (@lemenkov)          Jun 2018 - Jun 2018
   7. Vlad Patrascu (@rvlad-patrascu)     May 2017 - May 2017
   8. Razvan Pistolea                     Sep 2009 - Sep 2009

   (1) including any documentation-related commits, excluding
   merge commits

Chapter 3. Documentation

3.1. Contributors

   Last edited by: Bernard, Peter Lemenkov (@lemenkov), Liviu
   Chircu (@liviuchircu), Bogdan-Andrei Iancu (@bogdan-iancu),
   Razvan Pistolea.

   Documentation Copyrights:

   Copyright © 2009 Voice Sistem SRL
