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

<chapter>
	<chapterinfo>
	<revhistory>
		<revision>
		<revnumber>$Revision: 1827 $</revnumber>
		<date>$Date: 2007-03-12 17:22:53 +0200 (Mon, 12 Mar 2007) $</date>
		</revision>
	</revhistory>
	</chapterinfo>
	<title>User's Guide</title>
	
	<section>
	<title>Overview</title>
	<para>
		This module provides a way of communication between &sip; network 
		(via &sip MESSAGE) and <acronym>GSM</acronym> networks 
		(via ShortMessageService). Communication is possible from
		&sip; to <acronym>SMS</acronym> and vice versa. The module provides 
		facilities like <acronym>SMS</acronym> confirmation--the gateway can 
		confirm to the &sip; user if his message really reached its 
		destination as a <acronym>SMS</acronym>--or multi-part
		messages--if a &sip; messages is too long it will be split and sent 
		as multiple
		<acronym>SMS</acronym>.
	</para>
	<para>
		Errors occurred because of an invalid number or a too long message or 
		because of an internal modem malfunction are reported back to the 
		&sip; user via a &sip; message containing explanations regarding the 
		error.
	</para>
	<section>
		<title>Hardware Requirements</title>
		<para>
		The <acronym>SMS</acronym> module needs a <acronym>GSM</acronym> modem 
		to be able to send/receive the <acronym>SMS</acronym> messages. 
		Usually, this kind of modems are externals, linked to the machine via 
		serial cable. The modem can be a dedicated one (as the ones provided 
		by FALCOM) or can be a <acronym>GSM</acronym> telephone that
		has an internal modem (as the latest mobile phones from NOKIA and 
		ERICSSON).
		</para>
	</section>
	<section>
		<title>Numbering Plan</title>
		<para>
		The gateway accepts and advertises phone numbers in international 
		format, more specific like: +(international code)(area code)(number). 
		Ex: Germany, D1 = +49 170 5678181 Romania, Connex = +40 722 123456. 
		A number in this format is expected to be placed as username into 
		<acronym>RURI</acronym> or in the To header. If <acronym>RURI</acronym> 
		misses the username, the To header will be consider. Also,
		the gateway will advertise in this format the username in Contact
		headers (in &sip; replies and requests) and in From headers 
		(in &sip; requests).
		</para>
	</section>
	<section>
		<title>Address Mapping</title>
		<para>
		To identify the destination number of the <acronym>SMS</acronym>, the 
		gateway expects to have a mobile number in username of the &sip; 
		destination address (for example sip:+401704678811@sidomain.net). For 
		the reverse direction, because the gateway has only one 
		<acronym>GSM</acronym> number, the destination &sip; address has to be
		encapsulated into the <acronym>SMS</acronym> body. The gateway expects 
		to find a &sip; address at the beginning of the <acronym>SMS</acronym> 
		body in <quote>sip:user.host</quote> format. Everything before the 
		&sip; address will be discarded, the useful text begins exactly after 
		the address (for example 
		SMS=<quote>For sip:user@host hello world!!</quote> -> SIP=
		<quote>hello world</quote>) In order to facilitate replying, the 
		gateway sends all the <acronym>SMS</acronym> messages with a header 
		containing the source &sip; address in the following format: 
		<quote>From sip:user@host (if you reply DONOT remove 
		it)&lt;new_line&gt;</quote>. When an <acronym>SMS</acronym>-reply is 
		received having this header (all of it or truncated at the end), the 
		header will be left out (it will not be in the &sip; message).
		</para>
	</section>
	</section>

	<section>
	<title>Dependencies</title>
	<section>
		<title>&ser; Modules</title>
		<para>
		The following modules must be loaded before this module:
			<itemizedlist>
			<listitem>
			<para>
				<emphasis>tm - Transaction Manager</emphasis>.
			</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 loaded:
			<itemizedlist>
			<listitem>
			<para>
				<emphasis>None</emphasis>.
			</para>
			</listitem>
			</itemizedlist>
		</para>
	</section>
	</section>

	<section>
	<title>Exported Parameters</title>
	<section>
		<title><varname>modems</varname> (string)</title>
		<para>
		Define and configure one or more <acronym>GSM</acronym> modems.
		</para>
		<programlisting format="linespecific">
modems_value	 = modem_definition *( ";" modem_definition )
modem_definition = modem_name "[" list_of_params "]"
list_of_params   = modem_param *( ";" modem_param )
modem_param	  = name "=" value
</programlisting>
		<para>
		The following parameters can be used:
		</para>
		<itemizedlist>
		<listitem>
			<para>
			d=device (mandatory) - Device associated with modem 
			(/dev/ttyS0, /dev/modem, etc.).
			</para>
		</listitem>
		<listitem>
			<para>
			p=pin (optional) - <acronym>SIM</acronym> <acronym>PIN</acronym> - 
			default is NULL.
			</para>
		</listitem>
		<listitem>
			<para>
			m=mode (optional) - Modem working mode
			(<quote>ASCII</quote>,<quote>OLD</quote>,<quote>DIGICOM</quote>,
			<quote>NEW</quote>). Default value is <quote>NEW</quote>.
			</para>
		</listitem>
		<listitem>
			<para>
			c=SMS_Center (optional) - <acronym>SMS</acronym> center number for 
			that modem. Default is the <acronym>SMS</acronym> center set on the
			<acronym>SIM</acronym> card.
			</para>
		</listitem>
		<listitem>
			<para>
			b=baudrate (optional) - Default is 19600.
			</para>
		</listitem>
		<listitem>
			<para>
			r=retry (optional) - How many times to try to re-send a
			<acronym>SMS</acronym> that reported error. Default is twice.
			</para>
		</listitem>
		<listitem>
			<para>
			l=looping (optional) - Time for modem to wait before performing a 
			new check for incomimg/outgoing <acronym>SMS</acronym>/SIP_MSG.
			Default is 20.
			</para>
		</listitem>
		</itemizedlist>
		<para>
		<emphasis>
			No default value, the parameter is mandatory.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>modems</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("sms", "modems", "Nokia [d=/dev/ttyS1;b=9600;m=new;l=30] ")
modparam("sms", "modems", "Nokia[d=/dev/ttyS1];Siemens[d=/dev/ttyS2]")
...
</programlisting>
		</example>
	</section>

	<section>
		<title><varname>networks</varname> (string)</title>
		<para>
		Define and configure used <acronym>GSM</acronym> networks.
		</para>
		<programlisting format="linespecific">
networks_value = net_definition *( ";" net_definition )
net_definition = net_name "[" list_of_params "]"
list_of_params = set_param *( ";" set_param )
set_param	  = name "=" value
</programlisting>
		<para>
		The following parameters can be used:
		</para>
		<itemizedlist>
		<listitem>
			<para>
			m=msx_sms_per_call (optional) - Maximum number of 
			<acronym>SMS</acronym> send / received from that net in one modem 
			loop. Default is 10. This parameter was introduced to avoid 
			starvation.
			</para>
			<para>
			Example of the starvation--a modem can send 
			<acronym>SMS</acronym> for more than 1 networks. If you have a 
			huge number of <acronym>SMS</acronym> for the first network and 
			the number of incoming &sip; messages is equal to the sent
			<acronym>SMS</acronym> per same unit of time, the modem will 
			never get to send <acronym>SMS</acronym> for the next networks.
			</para>
		</listitem>
		</itemizedlist>
		<para>
		<emphasis>
			No default value, the parameter is mandatory.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>networks</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("sms", "networks", "D1 [m=10] ;d2[ m=20]")
...
</programlisting>
		</example>
	</section>

	<section>
		<title><varname>links</varname> (string)</title>
		<para>
		Define from which network each modem should send <acronym>SMS</acronym>.
		</para>
		<programlisting format="linespecific">
links_value = modem_assoc *( ";" modem_assoc )
modem_assoc = modem_name "[" list_of_networks "]"
list_of_networks = network *( ";" network )
</programlisting>
		<para>
		<emphasis>
			No default value, the parameter is mandatory.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>links</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("sms", "links", "NOKIA[D1;d2]")
...
</programlisting>
		</example>
		<para>
		The modem NOKIA will send <acronym>SMS</acronym> from D1 and D2 net 
		(in this order !). if in a net queue are more then max_sms_per_call 
		<acronym>SMS</acronym> the modem will <emphasis>not sleep</emphasis> 
		before starting the next loop ! Shortly, if messages are waiting to
		be sent, the modem will not go in sleep.
		</para>
	</section>

	<section>
		<title><varname>default_net</varname> (string)</title>
		<para>
		The default network to use. If no one specified, the first defined
		network is used. This parameter is useful only if the the 
		<quote>sms_send_msg</quote> exported function is used 
		(see <xref linkend="sec-exported-functions">).
		</para>
		<example>
		<title>Set <varname>default_net</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("sms", "default_net", "D1")
...
</programlisting>
		</example>
	</section>

	<section>
		<title><varname>max_sms_parts</varname> (integer)</title>
		<para>
		Shows in how many parts (<acronym>SMS</acronym> messages) a &sip; 
		message can be split. If exceeded, the &sip; message will be sent 
		truncated and the &sip; user will get back another message containing 
		the unsent part.
		</para>
		<para>
		<emphasis>
			Default value is 4.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>max_sms_parts</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("sms", "max_sms_parts", 10)
...
</programlisting>
		</example>
	</section>	

	<section>
		<title><varname>domain</varname> (string)</title>
		<para>
		Specify a fake domain name to be used by the gateway. The Contact 
		headers and the From header from request will be construct based on 
		this fake domain name. It's useful when the gateway is transparently 
		hidden behind a proxy/register (located on different machines).
		</para>
		<para>
		<emphasis>
			Default is the name of the machine the gateway is running on.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>domain_str</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("sms", "domain_str", "foo.bar")
...
</programlisting>
		</example>
	</section>

	<section>
		<title><varname>use_contact</varname> (integer)</title>
		<para>
		If a contact header should be added to the outgoing &sip; messages. 
		Even if the &sip; draft forbids this, some &uas; require it. 
		</para>
		<para>
		<emphasis>
			Default is 0 (no).
		</emphasis>
		</para>
		<example>
		<title>Set <varname>use_contact</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("sms", "use_contact", 1)
...
</programlisting>
		</example>
	</section>

	<section>
		<title><varname>sms_report_type</varname> (integer)</title>
		<para>
		If the modem should ask for <acronym>SMS</acronym> confirmation from the
		<acronym>SMS</acronym> Center. If the <acronym>SMSC</acronym> reply 
		with an error code, the gateway will send back to &sip; user a &sip; 
		message containing the text (or part of it) that couldn't be send. Two 
		report mechanisms are implemented:
		</para>
		<itemizedlist>
		<listitem>
			<para>
			1 - the reports are delivered by the <acronym>GSM</acronym> device 
			as <acronym>SMS</acronym> reports (so far supported only by Nokia 
			modems);
			</para>
		</listitem>
		<listitem>
			<para>
			2 - the reports are delivered as async. <acronym>CDS</acronym> 
			responses (supported by almost all modems, except Ericsson).
			</para>
		</listitem>
		</itemizedlist>
		<para>
		<emphasis>
			Default is 0 (no report).
		</emphasis>
		</para>
		<example>
		<title>Set <varname>sms_report_type</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("sms", "sms_report_type", 1)
...
</programlisting>
		</example>
	</section>	

	</section>
	<section id="sec-exported-functions">
	<title>Exported Functions</title>
	<section>
		<title>
		<function moreinfo="none">sms_send_msg_to_net(network_name)</function>
		</title>
		<para>
		Put the &sip; msg in the specified network queue. The function return 
		error if the number encapsulated into &sip; message is malformed, if 
		the content_type is incorrect or because of some internal failures.
		</para>
		<para>Meaning of the parameters is as follows:</para>
		<itemizedlist>
		<listitem>
			<para>
			<emphasis>network_name</emphasis> - Name of network.
			</para>
		</listitem>
		</itemizedlist>
		<para>
		This function can be used from REQUEST_ROUTE.
		</para>
		<example>
		<title><function>sms_send_msg_to_net</function> usage</title>
		<programlisting format="linespecific">
...
if (sms_send_msg_to_net("D1"))
{
	if (!t_reply("202", "yes sir, SMS sent over"))
	{
		# if replying failed, retry statelessly
		sl_reply_error();
	};
} else {
	if (!t_reply("502", "Bad gateway - SMS error"))
	{
		# if replying failed, retry statelessly
		sl_reply_error();
	};
	break;
};
...
</programlisting>
		</example>
	</section>

	<section>
		<title>
		<function moreinfo="none">sms_send_msg()</function>
		</title>
		<para>
		The same as the previous one, but use the default network queue.
		</para>
		<para>
		This function can be used from REQUEST_ROUTE.
		</para>
		<example>
		<title><function>sms_send_msg</function> usage</title>
		<programlisting format="linespecific">
...
if (sms_send_msg_to_net())
{
	if (!t_reply("202", "yes sir, SMS sent over"))
	{
		# if replying failed, retry statelessly
		sl_reply_error();
	};
} else {
	if (!t_reply("502", "Bad gateway - SMS error"))
	{
		# if replying failed, retry statelessly
		sl_reply_error();
	};
	break;
};
...
</programlisting>
		</example>
	</section>
	</section>
</chapter>

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