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

<chapter>

	<title>&adminguide;</title>

	<section>
	<title>Overview</title>
	<para>
		The User location module module keeps a user location table and
		provides access to the table for  other modules. The module exports no
		functions that can  be used directly from routing scripts.
	</para>
		<section id="usrloc.o.contact-matching-algs">
		<title>Contact matching</title>
		<para>
		How the contacts are matched (for the same AOR - Address of Record) is an
		important aspect of the usrloc module, especially in the context of NAT
		traversal - this raises more problems since contacts from different
		phones of the same user may overlap (if both are behind NATs with the same
		configuration) or the re-register contact of the same phone may be
		seen as a new one (due different binding via NAT).
		</para>
		<para>
		The SIP RFC 3261 publishes a matching algorithm based only on the
		contact string with Call-id and Cseq extra checking (if the Call-ID
		is the same, it must have a higher Cseq number, otherwise it is invalid).
		But as argued above, this is not enough in NAT traversal context,
		so the &kamailio; implementation of contact matching offers more algorithms:
		</para>
		<itemizedlist>
			<listitem>
			<para>
				<emphasis>Contact based only</emphasis> - it is strict RFC 3261
				compliancy - the Contact URI is matched as string and extra checked
				via Call-ID and cseq (if Call-ID is the same, it must have a
				higher cseq number, otherwise it is invalid).
			</para>
			</listitem>
			<listitem>
			<para>
				<emphasis>Contact and Call-id based</emphasis> - it is an extension
				of the first case - the contact and Call-ID must be matched as
				string; the cseq must be higher than the previous one - so be
				careful how you deal with REGISTER retransmissions in this
				case.
			</para>
			</listitem>
			<listitem>
			<para>
				<emphasis>contact and path based</emphasis> - it is an extension
				of the first case - the contact and path must be matched as
				string; the cseq must be higher than the previous one - so be
				careful how you deal with REGISTER retransmissions in this
				case.
			</para>
			</listitem>
			<listitem>
			<para>
				<emphasis>Call-id only based</emphasis> - it is not
				according to RFC3261, as it will check the Call-ID only
				(independent of the Contact-Header or Path).
			</para>
			</listitem>
		</itemizedlist>
		<para>
		To find out how to control/select the contact matching algorithm, please see the
		module parameter matching_mode - <xref linkend="usrloc.p.matching_mode"/>.
		</para>
		</section>
	</section>

	<section>
	<title>Dependencies</title>
	<section>
		<title>&kamailio; Modules</title>
		<para>
		The following modules must be loaded before this module:
			<itemizedlist>
			<listitem>
			<para>
				<emphasis>Optionally a database module</emphasis>.
			</para>
			</listitem>
			</itemizedlist>
		</para>
	</section>
	<section>
		<title>External Libraries or Applications</title>
		<para>
		The following libraries or applications must be installed before
		running &kamailio; with this module loaded:
			<itemizedlist>
			<listitem>
			<para>
				<emphasis>None</emphasis>.
			</para>
			</listitem>
			</itemizedlist>
		</para>
	</section>
	</section>
	<section>
	<title>Parameters</title>
	<section id="usrloc.p.nat_bflag">
		<title><varname>nat_bflag</varname> (int)</title>
		<para>
		The index of the branch flag to be used as NAT marker (if the contact
		is or not natted). This is a branch flag and it will be imported and
		used by all other modules depending of usrloc module.
		</para>
		<para>
		<emphasis>
			Default value is <quote>not set</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>nat_bflag</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "nat_bflag", 3)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.user_column">
		<title><varname>user_column</varname> (string)</title>
		<para>
		Name of database column containing usernames.
		</para>
		<para>
		<emphasis>
			Default value is <quote>username</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>user_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "user_column", "username")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.domain_column">
		<title><varname>domain_column</varname> (string)</title>
		<para>
		Name of database column containing domains.
		</para>
		<para>
		<emphasis>
			Default value is <quote>domain</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>user_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "domain_column", "domain")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.contact_column">
		<title><varname>contact_column</varname> (string)</title>
		<para>
		Name of database column containing contacts.
		</para>
		<para>
		<emphasis>
			Default value is <quote>contact</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>contact_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "contact_column", "contact")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.expires_column">
		<title><varname>expires_column</varname> (string)</title>
		<para>
		Name of database column containing expires value.
		</para>
		<para>
		<emphasis>
			Default value is <quote>expires</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>expires_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "expires_column", "expires")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.q_column">
		<title><varname>q_column</varname> (string)</title>
		<para>
		Name of database column containing q values.
		</para>
		<para>
		<emphasis>
			Default value is <quote>q</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>q_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "q_column", "q")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.callid_column">
		<title><varname>callid_column</varname> (string)</title>
		<para>
		Name of database column containing Call-ID values.
		</para>
		<para>
		<emphasis>
			Default value is <quote>callid</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>callid_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "callid_column", "callid")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.cseq_column">
		<title><varname>cseq_column</varname> (string)</title>
		<para>
		Name of database column containing Cseq.
		</para>
		<para>
		<emphasis>
			Default value is <quote>cseq</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>cseq_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "cseq_column", "cseq")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.methods_column">
		<title><varname>methods_column</varname> (string)</title>
		<para>
		Name of database column containing supported methods.
		</para>
		<para>
		<emphasis>
			Default value is <quote>methods</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>methods_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "methods_column", "methods")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.flags_column">
		<title><varname>flags_column</varname> (string)</title>
		<para>
		Name of database column to save the internal flags of the record.
		</para>
		<para>
		<emphasis>
			Default value is <quote>flags</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>flags_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "flags_column", "flags")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.cflags_column">
		<title><varname>cflags_column</varname> (string)</title>
		<para>
		Name of database column to save the branch/contact flags of the record.
		</para>
		<para>
		<emphasis>
			Default value is <quote>cflags</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>cflags_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "cflags_column", "cflags")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.user_agent_column">
		<title><varname>user_agent_column</varname> (string)</title>
		<para>
		Name of database column containing user-agent values.
		</para>
		<para>
		<emphasis>
			Default value is <quote>user_agent</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>user_agent_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "user_agent_column", "user_agent")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.received_column">
		<title><varname>received_column</varname> (string)</title>
		<para>
		Name of database column containing the source IP, port, and protocol from the REGISTER
		message.
		</para>
		<para>
		<emphasis>
			Default value is <quote>received</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>received_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "received_column", "received")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.socket_column">
		<title><varname>socket_column</varname> (string)</title>
		<para>
		Name of database column containing the received socket information (IP:port)
		for the REGISTER message.
		</para>
		<para>
		<emphasis>
			Default value is <quote>socket</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>socket_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "socket_column", "socket")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.path_column">
		<title><varname>path_column</varname> (string)</title>
		<para>
		Name of database column containing the Path header.
		</para>
		<para>
		<emphasis>
			Default value is <quote>path</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>path_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "path_column", "path")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.ruid_column">
		<title><varname>ruid_column</varname> (string)</title>
		<para>
		Name of database column containing the Kamailio record unique id.
		</para>
		<para>
		<emphasis>
			Default value is <quote>ruid</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>ruid_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "ruid_column", "myruid")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.instance_column">
		<title><varname>instance_column</varname> (string)</title>
		<para>
		Name of database column containing the SIP instance ID (GRUU - RFC5627).
		This is a unique device identifier - UUID.
		</para>
		<para>
		<emphasis>
			Default value is <quote>instance</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>instance_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "instance_column", "myinstance")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.reg_id_column">
		<title><varname>reg_id_column</varname> (string)</title>
		<para>
		Name of database table column containing the value for reg-id.
		</para>
		<para>
		<emphasis>
			Default value is <quote>reg_id</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>reg_id_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "reg_id_column", "r_id")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.server_id_column">
		<title><varname>server_id_column</varname> (string)</title>
		<para>
		Name of database table column containing the value for server id.
		</para>
		<para>
		<emphasis>
			Default value is <quote>server_id</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>server_id_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "server_id_column", "srv_id")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.connection_id_column">
		<title><varname>connection_id_column</varname> (string)</title>
		<para>
		Name of database table column containing the value for connection id.
		</para>
		<para>
		<emphasis>
			Default value is <quote>connection_id</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>connection_id_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "connection_id_column", "con_id")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.keepalive_column">
		<title><varname>keepalive_column</varname> (string)</title>
		<para>
		Name of database table column containing the value for keepalive status.
		</para>
		<para>
		<emphasis>
			Default value is <quote>keepalive</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>keepalive_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "keepalive_column", "kalive")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.partition_column">
		<title><varname>partition_column</varname> (string)</title>
		<para>
		Name of database table column containing the value for partition id.
		</para>
		<para>
		<emphasis>
			Default value is <quote>partition</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>partition_column</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "partition_column", "part")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.use_domain">
		<title><varname>use_domain</varname> (int)</title>
		<para>
		If the domain part of the user should be also saved and used for
		identifying the user (along with the username part). Useful in
		multi domain scenarios. Non 0 value means true.
		</para>
		<para>
		<emphasis>
			Default value is <quote>0 (false)</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>use_domain</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "use_domain", 1)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.desc_time_order">
		<title><varname>desc_time_order</varname> (int)</title>
		<para>
		If the user's contacts should be kept timestamp ordered; otherwise the
		contact will be ordered based on q value.
		Non 0 value means true.
		</para>
		<para>
		<emphasis>
			Default value is <quote>0 (false)</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>desc_time_order</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "desc_time_order", 1)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.timer_interval">
		<title><varname>timer_interval</varname> (int)</title>
		<para>
		Number of seconds between two timer runs. The module uses a timer to
		delete expired contacts, synchronize with database, send keepalives
		and other tasks, that need to be run periodically.
		</para>
		<para>
		<emphasis>
			Default value is 60.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>timer_interval</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "timer_interval", 120)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.db_url">
		<title><varname>db_url</varname> (string)</title>
		<para>
		&url; of the database that should be used.
		</para>
		<para>
		<emphasis>
			Default value is <quote>&defaultdb;</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>db_url</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "db_url", "&exampledb;")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.db_mode">
		<title><varname>db_mode</varname> (int)</title>
		<para>
		The usrloc module can utilize a database for persistent contact storage.
		If a database is used, the location database (contacts)  will survive
		machine restarts or software crashes. The disadvantage is that accessing 
		a database can be very time consuming. Therefore, usrloc module implements
		four database accessing modes:
		</para>
		<itemizedlist>
		<listitem>
			<para>
			0 - This disables database completely. Only memory will be used.
			Contacts will not survive restart. Use this value if you need a
			really fast usrloc and contact persistence is not necessary or
			is provided by other means.
			</para>
		</listitem>
		<listitem>
			<para>
			1 - Write-Through scheme. All changes to usrloc are immediately
			reflected in database too. This is very slow, but very reliable.
			Use this scheme if speed is not your priority but need to make
			sure that no registered contacts will be lost during crash or
			reboot.
			</para>
		</listitem>
		<listitem>
			<para>
			2 - Write-Back scheme. This is a combination of previous two
			schemes. All changes are made to memory and database
			synchronization is done in the timer. The timer deletes all
			expired contacts and flushes all modified or new contacts to
			database.  Use this scheme if you encounter high-load peaks
			and want them to process as fast as possible. The mode will
			not help at all if the load is high all the time.  Also, latency
			of this mode is much lower than latency of mode 1, but slightly
			higher than latency of mode 0.
			</para>
		</listitem>
		<listitem>
			<para>
			3 - DB-Only scheme. No memory cache is kept, all operations being
			directly performed with the database. The timer deletes all
			expired contacts from database - cleans after clients that didn't
			un-register or re-register. The mode is useful if you configure
			more servers sharing the same DB without any replication at SIP
			level. The mode may be slower due the high number of DB operation.
			For example NAT pinging is a killer since during each ping cycle
			all natted contact are loaded from the DB; The lack of memory
			caching also disable the statistics exports.
			</para>
		</listitem>
		<listitem>
			<para>
			4 - This uses database to load records at startup but uses only
			memory during the runtime. Records are not written back at all,
			not even at shutdown. Useful for scenarios when registrations are
			replicated to a node that does the storage in database during
			runtime.
			</para>
		</listitem>
		</itemizedlist>
		<warning>
		<para>
			In case of crash or restart contacts that are in memory only and
			haven't been flushed yet will get lost. If you want minimize the
			risk, use shorter timer interval.
		</para>
		</warning>
		<para>
		<emphasis>
			Default value is 0.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>db_mode</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "db_mode", 2)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.db_load">
		<title><varname>db_load</varname> (int)</title>
		<para>
		Determine if the usrloc module should load contacts from the database storage during module initialization
		A value of 0 disable the loading from the database, this parameter is ignored if db_mode 4 is set
		</para>
		<para>
		<emphasis>
			Default value is 1.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>db_load</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "db_load", 0)
...
		</programlisting>
		</example>
	</section>

	<section id="usrloc.p.db_insert_update">
		<title><varname>db_insert_update</varname> (int)</title>
		<para>
		Determine if the usrloc module should do an update when a duplicate key is found while inserting
		A value of 1 will activate update on duplicate key
		</para>
		<para>
		<emphasis>
			Default value is 0.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>db_insert_update</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "db_insert_update", 1)
...
		</programlisting>
		</example>
	</section>

	<section id="usrloc.p.matching_mode">
		<title><varname>matching_mode</varname> (int)</title>
		<para>
		What contact matching algorithm to be used. Refer to section
		<xref linkend="contact-matching-algs"/> for the description of the
		algorithms.
		</para>
		<para>
		The parameter may take the following values:
		</para>
		<itemizedlist>
			<listitem>
				<para><emphasis>0</emphasis> - CONTACT ONLY based matching
				algorithm.
				</para>
			</listitem>
			<listitem>
				<para><emphasis>1</emphasis> - CONTACT and CALLID based
				matching algorithm.
				</para>
			</listitem>
			<listitem>
				<para><emphasis>2</emphasis> - CONTACT and PATH based
				matching algorithm.  This mode is like mode <emphasis>0</emphasis>
				but allows for duplicate contacts from differing paths.
				If no path is available, it defaults to mode 0.
				</para>
			</listitem>
			<listitem>
				<para><emphasis>3</emphasis> - CALLID only based
				matching algorithm. This mode will discard any duplicate
				registration coming through different paths.
				</para>
			</listitem>
		</itemizedlist>
		<para>
		<emphasis>
			Default value is <emphasis>0 (CONTACT_ONLY)</emphasis>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>matching_mode</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "matching_mode", 1)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.cseq_delay">
		<title><varname>cseq_delay</varname> (int)</title>
		<para>
		Delay (in seconds) for accepting as retransmissions register requests
		with same Call-ID and Cseq. The delay is calculated starting from the
		receiving time of the first register with that Call-ID and Cseq.
		</para>
		<para>
		Retransmissions within this delay interval will be accepted and replied
		as the original request, but no update will be done in location. If the
		delay is exceeded, error is reported.
		</para>
		<para>
		A value of 0 disable the retransmission detection.
		</para>
		<para>
		<emphasis>
			Default value is <quote>20 seconds</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>cseq_delay</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "cseq_delay", 5)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.fetch_rows">
		<title><varname>fetch_rows</varname> (int)</title>
		<para>
		The number of the rows to be fetched at once from database
		when loading the location records. This value can be used
		to tune the load time at startup. For 1MB of private memory (default)
		it should be below 4000. The database driver must support
		fetch_result() capability.
		</para>
		<para>
		<emphasis>
			Default value is <quote>2000</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>fetch_rows</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "fetch_rows", 3000)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.hash_size">
		<title><varname>hash_size</varname> (int)</title>
		<para>
		The number of entries of the hash table used by usrloc to store the
		location records is 2^hash_size. For hash_size=4, the number of slots
		of the hash table is 16.
		</para>
		<para>
		<emphasis>
			Default value is <quote>10</quote> (1024 slots).
		</emphasis>
		</para>
		<example>
		<title>Set <varname>hash_size</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "hash_size", 12)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.preload">
		<title><varname>preload</varname> (string)</title>
		<para>
		Preload location table given as value. A location table is loaded
		based on fixup of registrar functions, therefore you need to use this
		parameter only to load tables that are not used by registrar module
		directly in configuration file.
		</para>
		<para>
		<emphasis>
			Default value is <quote>NULL</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>preload</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "preload", "location")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.db_update_as_insert">
		<title><varname>db_update_as_insert</varname> (int)</title>
		<para>
			Set this parameter if you want to do INSERT DB operations
			instead of UPDATE DB operations. It is recommended to set this parameter
			if you use Cassandra as a DB backend.
		</para>
		<para>
		<emphasis>
			Default value is <quote>0</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>db_update_as_insert</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "db_update_as_insert", 1)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.db_check_update">
		<title><varname>db_check_update</varname> (int)</title>
		<para>
			Set this parameter to 1 if you want to do DB INSERT if the number
			of affected rows by contact DB UPDATE operation is 0. The
			database module driver has to implement affected_rows() DB API
			function, otherwise this parameter is ignored - e.g., MySQL and
			Postgres DB connectors offer affected_rows().
		</para>
		<para>
		<emphasis>
			Default value is <quote>0</quote> (no DB INSERT).
		</emphasis>
		</para>
		<example>
		<title>Set <varname>db_check_update</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "db_check_update", 1)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.timer_procs">
		<title><varname>timer_procs</varname> (int)</title>
		<para>
			Number of timer processes to be started by module. Timer processes
			take care of checking expired records and synchronization with
			database. If set to 0, no dedicated timer is started, the one from
			core will be used.
		</para>

		<para>
			If the number of timer processes is greater than 1, the workload 
			of synchronization and record expiration is split up among the 
			multiple processes. (Each process is assigned a range of slots 
			from the internal hash table, and is responsible for cleanup and
			storage on those slots.)
		</para>
		<para>
		<emphasis>
			Default value is <quote>0</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>timer_procs</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "timer_procs", 4)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.xavp_contact">
		<title><varname>xavp_contact</varname> (string)</title>
		<para>
		The name of XAVP storing the attributes per contact. They are saved
		in location record and restored at lookup. The tm module parameter
		<varname>xavp_contact</varname> must also be set to the same value to use the
		<varname>t_load_contacts</varname> and <varname>t_next_contacts</varname> functions.
		</para>
		<para>
		<emphasis>
			Default value is <quote>NULL</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>xavp_contact</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("tm|usrloc", "xavp_contact", "ulattrs")
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.db_ops_ruid">
		<title><varname>db_ops_ruid</varname> (int)</title>
		<para>
			If set to 1, database queries for update or delete are done using
			ruid value. If it is set to 0, the old style using aor, contact and
			call-id is done.
		</para>
		<para>
		<emphasis>
			Default value is <quote>1</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>db_ops_ruid</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "db_ops_ruid", 0)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.handle_lost_tcp">
		<title><varname>handle_lost_tcp</varname> (int)</title>
		<para>
			If set to 1, Kamailio will remove location records made via
			TCP/TLS/WS/WSS transports when it looses corresponding tcp
            connections.  Does not currently work in DB-Only scheme.
		</para>
		<para>
		<emphasis>
			Default value is <quote>0</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>handle_lost_tcp</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "handle_lost_tcp", 1)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.close_expired_tcp">
		<title><varname>close_expired_tcp</varname> (int)</title>
		<para>
            If set to 1, Kamailio will close the TCP connection when a contact
            has expired, if the corresponding transport is TCP/TLS/WS/WSS.
        </para>
		<para>
		<emphasis>
			Default value is <quote>0</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>close_expired_tcp</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "close_expired_tcp", 1)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.expires_type">
		<title><varname>expires_type</varname> (int)</title>
		<para>
			If set to 1, &kamailio; expects to deal with BIGINT type on
			database columns for expires and last modified values. It
			allows to handle better the daylight time adjustments. If set
			to 0, those columns are expected to be on default type
			'DATETIME'. When it is 1, the database columns types have
			to be changed manually to 'BIGINT'.
		</para>
		<para>
		<emphasis>
			Default value is <quote>0</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>expires_type</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "expires_type", 1)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.db_raw_fetch_type">
		<title><varname>db_raw_fetch_type</varname> (int)</title>
		<para>
			This affect DB-only mode and controls what kind of
			raw query is used to fetch the contacts from database for
			specific needs (e.g., sending NAT keepalives). If it is set to 0,
			then the common SQL query is used (working for MySQL, PostgreSQL,
			...). If it is set to 1, the query required by Oracle is used.
		</para>
		<para>
		<emphasis>
			Default value is <quote>0</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>db_raw_fetch_type</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "db_raw_fetch_type", 1)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.db_insert_null">
		<title><varname>db_insert_null</varname> (int)</title>
		<para>
			If set to 1, the insert operation to database will add null values
			in the statement. It has to be set to 1 for the database systems
			that do not have table definitions that create automatically the
			null fields (e.g., db_mongodb) for each stored record.
		</para>
		<para>
			When set to 0, the fields that default to null are not
			added to the DB insert statement if they don't have a different
			value, making the query smaller.
		</para>
		<para>
		<emphasis>
			Default value is <quote>0</quote> (don't add null fields in insert
			statement).
		</emphasis>
		</para>
		<example>
		<title>Set <varname>db_insert_null</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "db_insert_null", 1)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.skip_remote_socket">
		<title><varname>skip_remote_socket</varname> (int)</title>
		<para>
			If set to 1, Kamailio will skip location record when loading from
			database, if socket value of the record does not in kamailio
			listening socket list.
		</para>
		<para>
		<emphasis>
			Default value is <quote>0</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>skip_remote_socket</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "skip_remote_socket", 1)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.db_timer_clean">
		<title><varname>db_timer_clean</varname> (int)</title>
		<para>
			Enable (1) or disable (0) cleaning of expired db records on
			timer basis for db_mode WRITE-BACK and WRITE-THROUGH. It uses
			the secondary timer process.
		</para>
		<para>
		<emphasis>
			Default value is <quote>0</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>db_timer_clean</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "db_timer_clean", 1)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.rm_expired_delay">
		<title><varname>rm_expired_delay</varname> (int)</title>
		<para>
			Specify the number of seconds to delay the removal of expired
			records. For now it works for DB_ONLY mode (db_mode=3).
		</para>
		<para>
		<emphasis>
			Default value is <quote>0</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>rm_expired_delay</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "rm_expired_delay", 30)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.server_id_filter">
		<title><varname>server_id_filter</varname> (int)</title>
		<para>
			Enable (1) or disable (0) filter records by server_id on load and
			during cleaning of expired db records. It could be useful when you
			want to use the same location table for several kamailio instances
			which are configured to work in db_mode=1 or db_mode=2 (cache modes).
			Otherwise one instance of proxy cleans records made by another proxy
			and that breaks its cache.
		</para>
		<para>
		<emphasis>
			Default value is <quote>0</quote>.
		</emphasis>
		</para>
		<example>
		<title>Set <varname>server_id_filter</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "server_id_filter", 1)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.version_table">
		<title><varname>version_table</varname> (int)</title>
		<para>
		If set to 0, the module will skip checking the version
		for location table.
		</para>
		<para>
		Default value is <quote>1 (check for table version)</quote>.
		</para>
		<example>
		<title><varname>version_table</varname> parameter usage</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "version_table", 0)
...
		</programlisting>
		</example>
	</section>

	<section id="usrloc.p.ka_mode">
		<title><varname>ka_mode</varname> (int)</title>
		<para>
		Keepalive mode - control the internal keepalive mechanism. With this feature
		enabled, the module sends periodically (based on timer interval) SIP requests
		to location contacts and measures the round trip in microseconds (the
		round trip value can be seen in the response of the RPC command 'ul.dump'). 
		</para>
		<para>
		Its value is a set of flags:
		</para>
		<itemizedlist>
		<listitem>
			<para>
			0 - if the value is zero, no keepalive is sent
			</para>
		</listitem>
		<listitem>
			<para>
			1 (bit 1 set) - if set to 1, the keepalive is enabled for all contacts
			</para>
		</listitem>
		<listitem>
			<para>
			2 (bit 2 set) - the keepalive is sent only for natted contacts
			(nat_bflag set)
			</para>
		</listitem>
		<listitem>
			<para>
			4 (bit 3 set) - the keepalive is sent only for UDP contacts
			</para>
		</listitem>
		</itemizedlist>
		<para>
		For example, if set to 6, then keepalive is sent only natted UDP contacs.
		</para>
		<para>
		Note: the internal keepalive of usrloc module conflicts in some way with
		the keepalive done by nathelper module. It is recommended to enable only
		one.
		</para>
		<para>
		Note: the internal keepalive is for the moment implemented only for
		contact records stored in memory.
		</para>
		<para>
		Note: it is recommeder to set 'timer_procs' parameter in order to have
		dedicated timer processes for usrloc module and off-load the keepalive
		sending process from the core timers.
		</para>
		<para>
		Default value is <quote>0 (keepalive disabled)</quote>.
		</para>
		<example>
		<title><varname>ka_mode</varname> parameter usage</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "ka_mode", 1)
...
		</programlisting>
		</example>
	</section>

	<section id="usrloc.p.ka_method">
		<title><varname>ka_method</varname> (str)</title>
		<para>
		The SIP method type for keepalive requests.
		</para>
		<para>
		Default value is <quote>OPTIONS</quote>.
		</para>
		<example>
		<title><varname>ka_method</varname> parameter usage</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "ka_method", "NOTIFY")
...
		</programlisting>
		</example>
	</section>

	<section id="usrloc.p.ka_from">
		<title><varname>ka_from</varname> (str)</title>
		<para>
		The SIP URI to be set in the From header of the keepalive requests.
		</para>
		<para>
		Default value is <quote>sip:server@kamailio.org</quote>.
		</para>
		<example>
		<title><varname>ka_from</varname> parameter usage</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "ka_from", "sip:server@mydomain.com")
...
		</programlisting>
		</example>
	</section>

	<section id="usrloc.p.ka_domain">
		<title><varname>ka_domain</varname> (str)</title>
		<para>
		The domain to be set in To header URI if the multi-domain is not enabled.
		If multi-domain is enabled, then the domain from the location record is
		used and this parameter is ignored.
		</para>
		<para>
		Default value is <quote>kamailio.org</quote>.
		</para>
		<example>
		<title><varname>ka_domain</varname> parameter usage</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "ka_domain", "mydomain.com")
...
		</programlisting>
		</example>
	</section>

	<section id="usrloc.p.ka_filter">
		<title><varname>ka_filter</varname> (int)</title>
		<para>
		Set filters for keepalive processing.
		</para>
		<para>
		Its value is a set of flags:
		</para>
		<itemizedlist>
		<listitem>
			<para>
			0 - if the value is zero, no filter is enabled for keepalives
			</para>
		</listitem>
		<listitem>
			<para>
			1 (bit 1 set) - keepalives sent only to records matching the
			server_id global parameter.
			</para>
		</listitem>
		</itemizedlist>
		<para>
		Default value is <quote>0</quote> (no filter).
		</para>
		<example>
		<title><varname>ka_filter</varname> parameter usage</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "ka_filter", 1)
...
		</programlisting>
		</example>
	</section>

	<section id="usrloc.p.ka_timeout">
		<title><varname>ka_timeout</varname> (int)</title>
		<para>
		The parameter sets the interval in seconds after which a
		contact is removed from location table if it does not reply to SIP
		keepalives (usually OPTIONS ping requests).
		</para>
		<para>
		The features is available only for contacts that are stored in memory
		(not working for db only mode of the usrloc module).
		</para>
		<para>
		Keepalives are sent stateless, not using TM module. The value of this
		parameter has to be few times higher than timer interval.
		</para>
		<para>
		<emphasis>
			Default value is <quote>0</quote> (feature disabled).
		</emphasis>
		</para>
		<example>
		<title>Set <varname>ka_timeout</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "ka_timeout", 120)
...
</programlisting>
		</example>
	</section>

	<section id="usrloc.p.ka_loglevel">
		<title><varname>ka_loglevel</varname> (int)</title>
		<para>
		The level to print the log message when the keepalive response is
		received. It should be a value between -5 (L_ALERT) and 3 (L_DBG).
		</para>
		<para>
		Default value is <quote>255</quote> (disabled).
		</para>
		<example>
		<title><varname>ka_loglevel</varname> parameter usage</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "ka_loglevel", 1)
...
		</programlisting>
		</example>
	</section>

	<section id="usrloc.p.ka_logmsg">
		<title><varname>ka_logmsg</varname> (str)</title>
		<para>
		The formatted log specification to be added to the message printed when
		the keepalive is received and roundtrip time is computed. The log
		message starts with "keepalive roundtrip: %u.%06u sec - ruid [%.*s]",
		then concatenates the value of this parameter and the end of line.
		</para>
		<para>
		The value of this parameter can contain script variables that are
		evaluated with the SIP response.
		</para>
		<para>
		Default value is <quote> to-uri: [$tu] remote-addr: [$sas]</quote>.
		</para>
		<example>
		<title><varname>ka_logmsg</varname> parameter usage</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "ka_logmsg", " to-uri: [$tu] remote-addr: [$sas]")
...
		</programlisting>
		</example>
	</section>

	<section id="usrloc.p.load_rank">
		<title><varname>load_rank</varname> (int)</title>
		<para>
		Allows to set the rank of the child SIP worker to load the location
		records.
		</para>
		<para>
		Default value is <quote>1</quote> (PROC_SIPINIT).
		</para>
		<example>
		<title><varname>load_rank</varname> parameter usage</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "load_rank", 1)
...
		</programlisting>
		</example>
	</section>

	<section id="usrloc.p.db_clean_tcp">
		<title><varname>db_clean_tcp</varname> (int)</title>
		<para>
			If set to 1, when &kamailio; starts it removes the contacts with
			transport TCP, TLS or WSS, no longer loading them. Useful when
			end points do not listen for incoming connections on contact address,
			which is quite common (end point use only tcp client connections).
			On restart, connections are lost, therefore the corresponding
			contact records become useless.
		</para>
		<para>
		Default value is <quote>0</quote> (do not clean tcp contacts).
		</para>
		<example>
		<title><varname>db_clean_tcp</varname> parameter usage</title>
		<programlisting format="linespecific">
...
modparam("usrloc", "db_clean_tcp", 1)
...
		</programlisting>
		</example>
	</section>

	</section>

	<section>
	<title>RPC Commands</title>

	<section id="usrloc.r.dump">
		<title>
		<function moreinfo="none">ul.dump</function>
		</title>
		<para>
		Dumps the content of the location table
		</para>
		<para>Parameters: </para>
		<itemizedlist>
			<listitem><para>
				None.
			</para></listitem>
		</itemizedlist>
	</section>
	<section id="usrloc.r.lookup">
		<title>
		<function moreinfo="none">ul.lookup table AOR</function>
		</title>
		<para>
		Looks up the contents of an AOR entry in the location table
		</para>
		<para>Parameters: </para>
		<itemizedlist>
			<listitem><para>
				<emphasis>table name</emphasis> - table where the AOR
				resides (Ex: location).
			</para></listitem>
			<listitem><para>
				<emphasis>AOR</emphasis> - user AOR in username[@domain]
				format (domain must be supplied only if use_domain option
				is on).
			</para></listitem>
		</itemizedlist>
	</section>
	<section id="usrloc.r.rm">
		<title>
		<function moreinfo="none">ul.rm table AOR</function>
		</title>
		<para>
		Deletes an entire AOR record (including its contacts).
		</para>
		<para>Parameters: </para>
		<itemizedlist>
			<listitem><para>
				<emphasis>table name</emphasis> - table where the AOR
				resides (Ex: location).
			</para></listitem>
			<listitem><para>
				<emphasis>AOR</emphasis> - user AOR in username[@domain]
				format (domain must be supplied only if use_domain option
				is on).
			</para></listitem>
		</itemizedlist>
	</section>
	<section id="usrloc.r.rm_contact">
		<title>
		<function moreinfo="none">ul.rm_contact table AOR contact</function>
		</title>
		<para>
		Deletes a contact from an AOR record.
		</para>
		<para>Parameters: </para>
		<itemizedlist>
			<listitem><para>
				<emphasis>table name</emphasis> - table where the AOR
				is removed from (Ex: location).
			</para></listitem>
			<listitem><para>
				<emphasis>AOR</emphasis> - user AOR in username[@domain]
				format (domain must be supplied only if use_domain option
				is on).
			</para></listitem>
			<listitem><para>
				<emphasis>contact</emphasis> - exact contact to be removed
			</para></listitem>
		</itemizedlist>
	</section>
	<section id="usrloc.r.flush">
		<title>
		<function moreinfo="none">ul.flush</function>
		</title>
		<para>
		Triggers the flush of USRLOC memory cache into DB.
		</para>
	</section>
	<section id="usrloc.r.add">
		<title>
		<function moreinfo="none">ul.add</function>
		</title>
		<para>
		Adds a new contact for an user AOR.
		</para>
		<para>Parameters: </para>
		<itemizedlist>
			<listitem><para>
				<emphasis>table name</emphasis> - table where the contact
				will be added (Ex: location).
			</para></listitem>
			<listitem><para>
				<emphasis>AOR</emphasis> - user AOR in username[@domain]
				format (domain must be supplied only if use_domain option
				is on).
			</para></listitem>
			<listitem><para>
				<emphasis>contact</emphasis> - contact string to be added
			</para></listitem>
			<listitem><para>
				<emphasis>expires</emphasis> - expires value of the contact
			</para></listitem>
			<listitem><para>
				<emphasis>Q</emphasis> - Q value of the contact
			</para></listitem>
			<listitem><para>
				<emphasis>path</emphasis> value with the Path vector (use '0'
				or '.' if it should not be set)
			</para></listitem>
			<listitem><para>
				<emphasis>flags</emphasis> - internal USRLOC flags of the
				contact
			</para></listitem>
			<listitem><para>
				<emphasis>cflags</emphasis> - per branch flags of the
				contact
			</para></listitem>
			<listitem><para>
				<emphasis>methods</emphasis> - mask with supported requests
				of the contact
			</para></listitem>
			<listitem><para>
				<emphasis>received</emphasis> (optional) value with the
				received-from address (source address) (use '0'
				or '.' if it should not be set). Format:
				sip:srcip:srcport;transport=abc
			</para></listitem>
			<listitem><para>
				<emphasis>socket</emphasis> (optional) value with the local
				socket address (use '0' or '.' if it should not be set). Format:
				proto:localip:localport
			</para></listitem>
		</itemizedlist>
		<para>
			Note: the position of parameters is relevant, in the case of
			optional parameters, use '0' or '.' for parameters that should not
			be set which are positioned before any parameter that has to be set.
		</para>
	</section>

	<section id="usrloc.r.db_users">
		<title>
		<function moreinfo="none">ul.db_users</function>
		</title>
		<para>
		Tell number of different users (AoRs) in a location table that have unexpired contacts.
		</para>
		<para>Parameters: </para>
		<itemizedlist>
			<listitem><para>
				<emphasis>table name</emphasis> - location table where the users are looked for, for example, location.
			</para></listitem>
		</itemizedlist>
	</section>

	<section id="usrloc.r.db_contacts">
		<title>
		<function moreinfo="none">ul.db_contacts</function>
		</title>
		<para>
		Tell number of unexpired contacts in a location table.
		</para>
		<para>Parameters: </para>
		<itemizedlist>
			<listitem><para>
				<emphasis>table name</emphasis> - location table where the contacts are looked for, for example, location.
			</para></listitem>
		</itemizedlist>
	</section>

	<section id="usrloc.r.db_expired_contacts">
		<title>
		<function moreinfo="none">ul.db_expired_contacts</function>
		</title>
		<para>
		Tell number of expired contacts in a location table.
		</para>
		<para>Parameters: </para>
		<itemizedlist>
			<listitem><para>
				<emphasis>table name</emphasis> - location table where the contacts are looked for, for example, location.
			</para></listitem>
		</itemizedlist>
	</section>

	</section><!-- RPC commands -->


	<section>
		<title>Statistics</title>
		<para>
		Exported statistics are listed in the next sections.
		</para>
		<section id="usrloc.s.users">
		<title>users</title>
			<para>
			Number of AOR existing in the USRLOC memory cache for that domain
			- can not be reset; this statistic will be register for each
			used domain (Ex: location).
			</para>
		</section>
		<section id="usrloc.s.contacts">
		<title>contacts</title>
			<para>
			Number of contacts existing in the USRLOC memory cache for that
			domain - can not be reset; this statistic will be register for
			each used domain (Ex: location).
			</para>
		</section>
		<section id="usrloc.s.expires">
		<title>expires</title>
			<para>
			Total number of expired contacts for that domain - can be reset;
			 this statistic will be register for each used domain
			(Ex: location).
			</para>
		</section>
		<section id="usrloc.s.registered_users">
		<title>registered_users</title>
			<para>
			Total number of AOR existing in the USRLOC memory cache for all
			domains - can not be reset.
			</para>
		</section>
	</section>


</chapter>