.. :maxdepth: 2

==========================
Load balancer installation
==========================

SIP flow with load-balancer
--------------------------------

.. raw:: html

	<embed>
	 <pre class='code xu mscgen_js' data-language='xu' data-named-style='basic'>
	msc {
  
	  arcgradient=0, hscale=2;
 
	  C[label="Call originator\n11.11.11.11"],
	  L[label="YETI Load balancer\n12.12.12.12"],
	  S[label="SEMS Node\n13.13.13.13"];
  
	  L alt S [label="POP", textbgcolor="#f7fff7"] {
	  C => L [label="INVITE"];
	  L => C [label="100 Trying"];
	  L => S [label="INVITE\nX-ORIG-IP:11.11.11.11.11\nX-ORIG-PORT:5060\nX-ORIG-PROTO:1"];
	  S rbox S [label= "Routing procedures"];
	  S => L [label="100 Trying"];
	  S => L [label="180 Ringing"];
	  L => C [label="180 Ringing"];
	  S => L [label="200 OK"];
	  L => C [label="200 OK"];
	  C >> S [label="RTP from originator"];
	  S >> C [label="RTP to originator"];
	  C => L [label="ACK"];
          L => S [label="ACK"];
          C => L [label="BYE"];
          L => S [label="BYE"];
          S => L [label="200 OK"];
	  L => C [label="200 OK"];
	  S rbox S [label= "CDR writing"];
	  };
	}

    </pre>
    </embed>


Packages installation
---------------------

Install **kamailio** packages using system repository or https://deb.kamailio.org/ . Example kamailio configuration present at out yeti-lb repository: https://github.com/yeti-switch/yeti-lb/tree/master/src


.. warning:: You should register your Load balancer instance as trusted load balancer. See :ref:`System->Load balancers <load_balancers>` menu.


Launch
------

Launch load balancer:

.. code-block:: console

    root@server:~# service kamailio start

Checks
------

Check kamailio running and listening desired sockets:

.. code-block:: console

    root@server:~# pgrep kamailio
    30853
    30854
    30855
    30856
    30857
    root@server:~# netstat -lpn | grep kamailio
    tcp 0 0 127.0.0.1:5060 0.0.0.0:* LISTEN 30857/kamailio 
    udp 0 0 127.0.0.1:5060 0.0.0.0:* 30853/kamailio
    raw 0 0 0.0.0.0:255 0.0.0.0:* 7 30853/kamailio
    unix 2 [ ACC ] STREAM LISTENING 2673337 30856/kamailio /var/run/kamailio//kamailio_ctl

Check for /var/log/syslog on possible errors.

Also you can run daemon in foreground
with logging to stderr for debugging purposes:

.. code-block:: console

    root@server:~# kamailio /etc/kamailio/kamailio.cfg