pua dialoginfo

Anca-Maria Vamanu

   voice-system.ro

Edited by

Anca-Maria Vamanu

Klaus Darilion

   IPCom (Module implementation was partly sponsored by Silver
   Server (www.sil.at))

Edited by

Klaus Darilion

   IPCom

   Copyright  2006 voice-system.ro

   Copyright  2008 Klaus Darilion IPCom
   Revision History
   Revision $Revision: 4594 $ $Date: 2008-08-06 12:08:33 +0200
                              (Wed, 06 Aug 2008) $
     __________________________________________________________

   Table of Contents

   1. Admin Guide

        1.1. Overview
        1.2. Dependencies

              1.2.1. OpenSIPS Modules
              1.2.2. External Libraries or Applications

        1.3. Exported Parameters

              1.3.1. include_callid (int)
              1.3.2. include_tags (int)
              1.3.3. include_localremote (int)
              1.3.4. caller_confirmed (int)
              1.3.5. presence_sever (string)

        1.4. Exported Functions

   List of Examples

   1.1. Set include_callid parameter
   1.2. Set include_tags parameter
   1.3. Set include_localremote parameter
   1.4. Set caller_confirmed parameter
   1.5. Set presence_server parameter

Chapter 1. Admin Guide

1.1. Overview

   The pua_dialoginfo retrieves dialog state information from the
   dialog module and PUBLISHes the dialog-information using the
   pua module. Thus, in combination with the presence_xml module
   this can be used to derive dialog-info from the dialog module
   and NOTIFY the subscribed watchers about dialog-info changes.
   This can be used for example with SNOM and Linksys phones.

   Note: This implements dialog-info according to RFC 4235 and is
   not compatible with the BLA feature defined in
   draft-anil-sipping-bla-03.txt. (Actually the BLA draft is
   really crap as it changes SIP semantics)

   The module is based on code (copy/paste) from pua_usrloc and
   nat_traversal module.

   Following you will show some examples of an dialog-info XML
   document taken from RFC 4235. This will help you to understand
   the meaning of the module parameters:

<?xml version="1.0"?>
<dialog-info xmlns="urn:ietf:params:xml:ns:dialog-info"
             version="1"
             state="full"
             entity="sip:alice@example.com">
    <dialog id="as7d900as8"
            call-id="a84b4c76e66710"
            local-tag="1928301774"
            remote-tag="456887766"
            direction="initiator">
        <state>early</state>
    </dialog>
</dialog-info>


   The root element is the "dialog-info". It contains the
   namespace, the version (which must be incremented for each new
   PUBLISH for this certain dialog), the state (this module only
   supports state=full) and the entity for which we publish the
   dialog-info.

   The "dialog" element must contain an id parameter. The id
   parameter is usually different to the optional call-id
   parameter (which is the call-id of the INVITE request) as an
   INVITE can create multiple dialogs (forked request). But as the
   dialog module does not support multiple dialogs created by a
   single transaction, the pua_dialoginfo module sets the id
   parameter to the same value as the call-id parameter. The
   "local-tag" indicates the local tag of the entity. The
   remote-tag indicates the tag of the remote party. The
   "direction" indicates if the entity was the initator of the
   dialog or the recepient (aka if the entity sent or received the
   first INVITE).

   The "state" element describes the state of the dialog state
   machine and must be either: trying, proceeding, early,
   confirmed or terminated.

   The dialog element can contain optional "local" and "remote"
   elements which decsribes the local and the remote party in more
   detail, for example:

<?xml version="1.0" encoding="UTF-8"?>
<dialog-info xmlns="urn:ietf:params:xml:ns:dialog-info"
             version="1" state="full">
    <dialog id="as7d900as8"
            call-id="a84b4c76e66710"
            local-tag="1928301774"
            remote-tag="456887766"
            direction="initiator">
        <state>early</state>
        <local>
            <identity display="Alice">sip:alice@example.com</identity>
            <target uri="sip:alice@phone11.example.com"/>
        </local>
        <remote>
            <identity display="Bob">sip:bob@example.org</identity>
            <target uri="sip:bobster@phone21.example.org"/>
        </remote>
    </dialog>
</dialog-info>


   The local and remote elements are needed to implement call
   pickup. For example if the above XML document is received by
   somebody who SUBSCRIBEd the dialog-info of Alice, then it can
   pick-up the call by sending an INVITE to Bob (actually I am not
   sure if it should use the URI in the identity element or the
   URI in the target parameter) which contains a Replaces header
   which contains the call-id and the tags. This was tested
   sucessfully with Linksys SPA962 phones and with SNOM 320
   Firmware 7.3.7 (you have to set the function key to
   "Extension").

   A dialog-info XML document may contain multiple "dialog"
   elements, for example if the entity has multiple ongoing
   dialogs. For example the following XML document shows a
   confirmed dialog and an early (probably a second incoming call)
   dialog.

<?xml version="1.0"?>
<dialog-info xmlns="urn:ietf:params:xml:ns:dialog-info"
             version="3"
             state="full"
             entity="sip:alice@example.com">
    <dialog id="as7d900as8" call-id="a84b4c76e66710"
            local-tag="1928301774" remote-tag="hh76a"
            direction="initiator">
        <state>confirmed</state>
    </dialog>
    <dialog id="j7zgt54" call-id="ASDRRVASDRF"
            local-tag="123456789" remote-tag="EE345"
            direction="recipient">
        <state>early</state>
    </dialog>
</dialog-info>


   As the dialog module callbacks only address a certain dialog,
   the pua_dialoginfo always PUBLISHes XML documents with a single
   "dialog" element. If an entity has multiple concurrent dialogs,
   the pua_dialoginfo module will send PUBLISH for each dialog.
   These multiple "presenties" can be aggregated by the
   presence_dialoginfo module into a single XML document with
   multiple "dialog" elements. Please see the description of the
   presence_dialoginfo module for details about the aggregation.

   If there are problems with the callbacks from dialog module and
   you want to debug them you define PUA_DIALOGINFO_DEBUG in
   pua_dialoginfo.c and recompile.

   Known issues:
     * The module tries to find out if the entity is a local user.
       Only PUBLISH to local user are sent. Therefore, the module
       needs to find out if the domain is a local one or not. It
       uses the same mechanism as the "==myself" mechanism. Thus,
       all domains have to be declared with the "alias=..." option
       in OpenSIPS.cfg. DB-based multidomain support as offered by
       "domain" module is not supported yet. Conclusion: The
       module has the same "domain" problems as the "rr" module.
     * The module puts the call-id of the dialog into an XML
       parameter. Thus, if the call-id contains quotes, they
       should be escaped. This is not yet implemented. Thus, if
       the call-id contains quotes the XML document will be
       invalid.
     * The module derives the AoR of the callee from the To:
       header. Thus, if the To header does not contain the
       canonical AoR the PUBLISH might have the wrong SIP URI in
       the RURI and the entity parameter.

1.2. Dependencies

1.2.1. OpenSIPS Modules

   The following modules must be loaded before this module:
     * dialog.
     * pua.

1.2.2. External Libraries or Applications

   The following libraries or applications must be installed
   before running OpenSIPS with this module loaded:
     * libxml.

1.3. Exported Parameters

1.3.1. include_callid (int)

   If this parameter is set, the optional call-id will be put into
   the dialog element. This is needed for call-pickup features.

   Default value is "1".

   Example 1.1. Set include_callid parameter
...
modparam("pua_dialoginfo", "include_callid", 0)
...

1.3.2. include_tags (int)

   If this parameter is set, the local and remote tag will be put
   into the dialog element. This is needed for call-pickup
   features.

   Default value is "1".

   Example 1.2. Set include_tags parameter
...
modparam("pua_dialoginfo", "include_tags", 0)
...

1.3.3. include_localremote (int)

   If this parameter is set, the optional local and remote
   elements will be put into the dialog element. This is needed
   for call-pickup features.

   Default value is "1".

   Example 1.3. Set include_localremote parameter
...
modparam("pua_dialoginfo", "include_localremote", 0)
...

1.3.4. caller_confirmed (int)

   Usually the dialog-info of the caller will be "trying -> early
   -> confirmed" and the dialog-info of the callee will be "early
   -> confirmed". On some phones the function LED will start
   blinking if the state is early, regardless if is is the caller
   or the callee (indicated with the "direction" parameter). To
   avoid blinking LEDs for the caller, you can enable this
   parameter. Then the state of the caller will be singaled as
   "confirmed" even in "early" state. This is a workaround for the
   buggy Linksys SPA962 phones. SNOM phones work well with the
   default setting.

   Default value is "0".

   Example 1.4. Set caller_confirmed parameter
...
modparam("pua_dialoginfo", "caller_confirmed", 1)
...

1.3.5. presence_sever (string)

   The address of the presence server, where the PUBLISH messages
   should be sent ( not compulsory).

   Example 1.5. Set presence_server parameter
...
modparam("pua_dialoginfo", "presence_server", "sip:ps@opensips.org:5060"
)
...

1.4. Exported Functions
