<!-- Module User's Guide -->

<chapter>
    <chapterinfo>
	<revhistory>
	    <revision>
		<revnumber>$Revision: 1.2 $</revnumber>
		<date>$Date: 2003/07/16 15:17:04 $</date>
	    </revision>
	</revhistory>
    </chapterinfo>
    <title>User's Guide</title>
    
    <section>
	<title>Overview</title>
	<para>
	    This modules provides offline message storage for the &sername;. It stores received
	    messages for an offline user and sends them when the user becomes online.
	</para>
	<para>
	    For each message, the modules stores <quote>Request-URI</quote> (<quote>R-URI</quote>)
	    only if it is a complete address of record (<quote>username@hostname</quote>), &uri;
	    from <quote>To</quote> header, &uri; from <quote>From</quote> header, incoming time,
	    expiration time, content type and body of the message. If <quote>R-URI</quote> is not an
	    address of record (it might be the contact address for current &sip; session) the &uri;
	    from <quote>To</quote> header will be used as <abbrev>R-URI</abbrev>.
	</para>
	<para>
	    When the expiration time passed, the message is discarded from database.  Expiration
	    time is computed based on incoming time and one of the module's parameters.
	</para>
	<para>
	    Every time when a user registers with &ser;, the module is looking in database for offline
	    messages intended for that user. All of them will be sent to contact address provided in
	    REGISTER request.
	</para>
	<para>
	    It may happen the &sip; user to be registered but his &sip; User Agent to have no
	    support for MESSAGE request. In this case it should be used the
	    <quote>failure_route</quote> to store the undelivered requests.
	</para>
    </section>
    <section>
	<title>Dependencies</title>
	<section>
	    <title>&ser; modules</title>
	    <para>
		The following modules must be loaded before this module:
	    	<itemizedlist>
		    <listitem>
			<para>
			    <emphasis>database module</emphasis> - mysql, dbtext or other module
			    that implements the <quote>db</quote> interface and provides support for
			    storing/receiving data to/from a database system.
			</para>
		    </listitem>
		    <listitem>
			<para>
			    <emphasis>TM</emphasis>--transaction module--is used to send &sip;
			    requests.
			</para>
		    </listitem>
	    	</itemizedlist>
	    </para>
	</section>
	<section>
	    <title>External libraries or applications</title>
	    <para>
		The following libraries or applications must be installed before running &ser; with
		this module:
	    	<itemizedlist>
		    <listitem>
			<para>
			    <emphasis>none</emphasis>.
			</para>
		    </listitem>
	    	</itemizedlist>
	    </para>
	</section>
    </section>
    <section>
	<title>Exported Parameters</title>
	<section>
	    <title><varname>db_url</varname> (string)</title>
	    <para>
		Database &url;.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>sql://root@localhost/msilo</quote>.
		</emphasis>
	    </para>
	    <example>
		<title>Set the <quote>db_url</quote> parameter</title>
		<programlisting format="linespecific">
...
modparam("msilo", "db_url", "sql://user:passwd@host.com/dbname")
...
</programlisting>
	    </example>
	</section>
	<section>
	    <title><varname>db_table</varname> (string)</title>
	    <para>
		The name of table where to store the messages.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>silo</quote>.
		</emphasis>
	    </para>
	    <example>
		<title>Set the <quote>db_table</quote> parameter</title>
<programlisting format="linespecific">
...
modparam("msilo", "db_table", "silo")
...
</programlisting>
	    </example>
	</section>
	<section>
	    <title><varname>registrar</varname> (string)</title>
	    <para>
		The &sip; address used to inform users that destination of their message is not
		online and the message will be delivered next time when that user goes online. If
		the parameter is not set, the module will not send any notification. All requests
		intended for this &sip; address will not be stored for lately delivery.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>NULL</quote>.
		</emphasis>
	    </para>
	    <example>
		<title>Set the <quote>registrar</quote> parameter</title>
<programlisting format="linespecific">
...
modparam("msilo", "registrar", "sip:registrar@iptel.org")
...
</programlisting>
	    </example>
	</section>
	<section>
	    <title><varname>expire_time</varname> (int)</title>
	    <para>
		Expire time of stored messages - seconds. When this time passed, the message is
		silently discarded from database.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>259200 (72 hours = 3 days)</quote>.
		</emphasis>
	    </para>
	    <example>
		<title>Set the <quote>expire_time</quote> parameter</title>
<programlisting format="linespecific">
...
modparam("msilo", "expire_time", 36000)
...
</programlisting>
	    </example>
	</section>
	<section>
	    <title><varname>check_time</varname> (int)</title>
	    <para>
		Timer interval to check if dumped messages are sent OK - seconds. The module keeps
		each request send by itself for a new online user and if the reply is 2xx then the
		message is deleted from database.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>30</quote>.
		</emphasis>
	    </para>
	    <example>
		<title>Set the <quote>check_time</quote> parameter</title>
		<programlisting format="linespecific">
...
modparam("msilo", "check_time", 10)
...
</programlisting>
	    </example>
	</section>
	<section>
	    <title><varname>clean_period</varname> (int)</title>
	    <para>
		Number of <quote>check_time</quote> cycles when to check if
		there are expired messages in database.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>5</quote>.
		</emphasis>
	    </para>
	    <example>
		<title>Set the <quote>clean_period</quote> parameter</title>
		<programlisting format="linespecific">
...
modparam("msilo", "clean_period", "3")
...
</programlisting>
	    </example>
	</section>
	<section>
	    <title><varname>use_contact</varname> (int)</title>
	    <para>
		Turns on/off the usage of the Contact address to send notification back to sender
		whose message is stored by MSILO.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>1 (0 = off, 1 = on)</quote>.
		</emphasis>
	    </para>
	    <example>
		<title>Set the <quote>param_name</quote> parameter</title>
<programlisting format="linespecific">
...
modparam("msilo", "use_contact", 0)
...
</programlisting>
	    </example>
	</section>
    </section>
    <section>
	<title>Exported Functions</title>
	<section>
	    <title><function moreinfo="none">m_store(mode)</function></title>
	    <para>
		The method stores certain parts of the current &sip; request (it should be called
		when the request type is MESSAGE and the destination user is offline or his &ua does
		not support MESSAGE requests). If the user is registered with a UA which does not
		support MESSAGE requests you should not use mode=<quote>0</quote> if you have
		changed the request uri with the contact address of user's &ua;.
	    </para>
	    <para>Meaning of the parameters is as follows:</para>
	    <itemizedlist>
		<listitem>
		    <para>
			<emphasis>mode</emphasis> - specifies what to save as R-URI.
		    </para>
		    <itemizedlist>
			<listitem>
			    <para>
				<quote>0</quote> - first check if new_uri is an address of
				record. If yes, then use it and store it as R-URI, otherwise look at
				R-URI and, if necessary, at &uri; from <quote>To</quote> header.
			    </para>
			</listitem>
			<listitem>
			    <para>
				<quote>1</quote> - look first at R-URI and then at &uri; from
				<quote>To</quote> header.
			    </para>
			</listitem>
			<listitem>
			    <para>
				<quote>2</quote> - look only at &uri; form <quote>To</quote> header.
			    </para>
			</listitem>
		    </itemizedlist>
		</listitem>
	    </itemizedlist>
	</section>
	<section>
	    <title><function moreinfo="none">m_dump()</function></title>
	    <para>
		The method sends stored messages for the &sip; user that is going to register to his
		actual contact address. The method should be called when a REGISTER request is
		received and the <quote>Expire</quote> header has a value greater than zero.
	    </para>
	</section>
    </section>
    <section>
	<title>Installation & Running</title>
	<section>
	    <title>Database setup</title>
	    <para>
		Before running &ser; with msilo, you have to setup the database table where the
		module will store the message. For that, if the table was not created by the
		installation script or you choose to install everything by yourself you can use the
		following <acronym>SQL</acronym> script (good for MySQL) as template. Database and
		table name can be set with module parameters so they can be changed, but the name of
		the columns must be as they are in the next <acronym>SQL</acronym> script.
	    </para>
	    <example>
		<title>msilo sql script</title>
		<programlisting format="linespecific">
...
&msilosql;
...
</programlisting>
		</example>
    	</section>
	
    	<section>
	    <title>&ser; config file</title>
	    <para>
		Next picture displays a sample usage of msilo.
	    </para>
	    <example>
		<title>&ser; config script - sample msilo usage</title>
		<programlisting format="linespecific">
...
&msilocfg;
...
		</programlisting>
	    </example>
	</section>
    </section>
</chapter>

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