1.1. Overview

This modules is a gateway between Openser and a jabber server. It enables the exchange of instant messages between SIP clients and XMPP(jabber) clients.

The gateway has two modes to run:

• the component-mode - the gateway requires a standalone XMPP server amd the 'xmpp' module acts as a XMPP component

• the server-mode - the module acts itself as a XMPP server, no requirement for another XMPP server in the system. NOTE: this is limited implementation of a XMPP server, it does not support SRV or TLS so far. This mode is in beta stage for the moment.

In the component mode, you need a local XMPP server (recommended Jabberd2); the xmpp module will relay all your connections to a tcp connection to the local jabber server. The documentation and the source for a Jabber server are located at the following link: http://jabberd.jabberstudio.org/2/#download

After you have a running XMPP server, what you need to do is set the following parameters in the Openser configuration file:

• gateway_domain, xmpp_domain (which can be the same as gateway_domain) and xmpp_host, which are explained in the Exported Parameters section;

• listen = your ip;

• alias=openser domain and alias=gateway domain;

• in the following section of the configuration file, change to your gateway domain:

 	 ### ---8<--- cut here ---8<--- ###
	if (avp_check("$rd", "eq/s:sip-xmpp.openser.org")) {
		if (!t_newtran()) {
			sl_reply_error();
	...........	 

• you can also change the jabber server password, which must be the same as the xmpp_password parameter.

A use case, for the component-mode, would look like this:

• Openser is running on sip-server.openser.org;

• the gateway is running on sip-xmpp.openser.org;

• the jabber server is running on xmpp.openser.org;

• the component is running on xmpp-sip.openser.org.

In the server mode, the xmpp module is a minimal jabber server, thus you do not need to install another jabber server, the gateway will connect to the jabber servers, where the users you want to chat with have an account.

If you want to change to server-mode, you have to change the "backend" parameter, as shown in the Exported Parameters section, from component to server.

A use case, for the server-mode, would look like this:

• Openser is running on sip-server.openser.org;

• the gateway is running on sip-xmpp.openser.org;

• the "XMPP server" is running on xmpp-sip.openser.org.

In both cases, the destination address must have the same pattern:

"sip:username<delim>jabber_server@gateway_domain"

From a jabber client's point of view, the destination will look like:

"sip_username<delim>openser_domain@xmpp_domain"

1.2. Dependencies

1.3. Exported Parameters

...
 modparam("xmpp", "backend", "server");
...

...
 modparam("xmpp", "domain_separator", "*");
...

...
 modparam("xmpp", "gateway_domain", "sip-xmpp.openser.org");
...

...
 modparam("xmpp", "xmpp_domain", "xmpp-sip.openser.org");
...

...
 modparam("xmpp", "xmpp_host", "xmpp.openser.org");
...

...
 modparam("xmpp", "xmpp_port", "5269");
...

			<router>
	............... 
	<!-- Username/password to authenticate as --&gt;
    <user>jabberd</user>;          <!-- default: jabberd -->;
    <pass>secret</pass>;           <!-- default: secret -->;	
			

...
 modparam("xmpp", "xmpp_password", "secret");
...

1.4. Exported Functions

...
xmpp_send_massage();
...

1.5. Configuration

Next is presented a sample configuration file one can use to implement a standalone SIP-to-XMPP gateway. You can run an instance of OpenSER on a separate machine or on different port with the following config, and have the main SIP server configured to forward all SIP requests for XMPP world to it.

....
#
# $Id: openser-xmpp.cfg 1514 2007-01-16 17:01:22Z bogdan_iancu $
#
# simple quick-start config script for XMPP GW
#
# make sure in your main SIP server that you send
# only the adequate SIP MESSAGES to XMPP GW
#
#
# ----------- global configuration parameters ------------------------

debug=9            # debug level (cmd line: -dddddddddd)
fork=no
log_stderror=yes    # (cmd line: -E)

/* Uncomment these lines to enter debugging mode 
fork=no
log_stderror=yes
*/

check_via=no	# (cmd. line: -v)
dns=no          # (cmd. line: -r)
rev_dns=no      # (cmd. line: -R)
children=4

listen=udp:10.10.10.10:5076
alias=sip-xmpp.openser.org

# ------------------ module loading ----------------------------------

mpath="/usr/local/openser-1.1.0-xmpp/lib/openser/modules/"
loadmodule "sl.so"
loadmodule "tm.so"
loadmodule "rr.so"
loadmodule "maxfwd.so"
loadmodule "textops.so"
loadmodule "mi_fifo.so"


# XMPP
loadmodule "xmpp.so"

modparam("xmpp", "domain_separator", "*")
modparam("xmpp", "gateway_domain", "sip-xmpp.openser.org")
modparam("xmpp", "xmpp_domain", "xmpp-sip.openser.org")
modparam("xmpp", "xmpp_host", "xmpp.openser.org")

modparam("xmpp", "backend", "server")
# modparam("xmpp", "backend", "component")

# ----------------- setting module-specific parameters ---------------

# -- mi_fifo params --

modparam("mi_fifo", "fifo_name", "/tmp/openser_fifo_xmpp")

# -- usrloc params --

# -- rr params --
# add value to ;lr param to make some broken UAs happy
modparam("rr", "enable_full_lr", 1)

# -------------------------  request routing logic -------------------

# main routing logic

route{

	# initial sanity checks -- messages with
	# max_forwards==0, or excessively long requests
	if (!mf_process_maxfwd_header("10")) {
		sl_send_reply("483","Too Many Hops");
		exit;
	};

	if (msg:len >=  2048 ) {
		sl_send_reply("513", "Message too big");
		exit;
	};

	### absorb retransmissions ###
	if (!t_newtran()) {
		sl_reply_error();
		return;
	}
	if (method == "MESSAGE") {
		log("*** xmpp-handled MESSAGE message.\n");
		if (xmpp_send_message()) {
			t_reply("200", "Accepted");
		} else {
			t_reply("404", "Not found");
		}
		return;
	}
		
	log("*** xmpp: unhandled message type\n");
	t_reply("503", "Service unavailable");
	return;
}


....