Hi Daniel, thank you for the reply. I have some more questions to ask. 1. Since the dial plan is configured exactly on Asterisk (at etc/asterisk/sip.conf and /etc/asterisk/extension.conf), do we need to enable MySQL for Kamailio installation? Or the default installation configuration will do (without additional dialplan or MySQL setting)? My idea is only using Kamailio as pure load balancer so we hope to do this as simple as possible without degrading the function. 2. I assume using Kamailio dispatcher module will forward some of the users to asterik server 1 and some of them to asterisk server 2. Then if user A is registered with Asterisk server 1 and user B is registered with Asterisk server 2, can user A call user B? Without Kamailio, the answer is no since they are in different Asterisk server. With Kamailio, I am expecting both user A and B can call each other although they are registered with different servers. Is my configuration enough to achieve this function? Or do we need some additional setup for this? Thanks again. Best Regards, Kurt On Mon, Apr 27, 2009 at 8:02 PM, Daniel-Constantin Mierla &lt;miconda(a)gmail.com <mailto:miconda@gmail.com>> wrote: Hello, On 04/27/2009 07:10 AM, Kurt Weasel wrote: Hi, I searched around the web to load balance asterisk servers and found Kamailio for possible solution. Let's say I have two identical asterisk servers with same dialplan and configuration and I want both servers look like they have same IP address from clients. Based on my understanding, we need 1 Kamailio as load balancer and 2 Asterisk servers as the real servers. Let's say the setup is : Kamailio load balancer 192.168.2.1 Asterisk Server #1 192.168.2.2 Asterisk Server #2 192.168.2.3 My question is, X-Lite softphone Configuration should be set to domain 192.168.2.1, right? I also want to know the step by step configuration to set kamailio as load balancer. I have not used Kamailio before. However after searching the documentation, the step (based on my understanding) is somewhat like this : 1. Install Kamailio. I will use the step by step here : http://kamailio.org/dokuwiki/doku.php/install:kamailio-1.5.x-from-svn 2. Then, using dipatcher module, I will configure it using this guide here : http://kamailio.org/dokuwiki/doku.php/asterisk:load-balancing-and-ha Then modify the dispatcher.list file to match the IP address of my asterisk servers : /1 sip:192.168.2.2:5060 <http://192.168.2.2:5060> <http://192.168.2.2:5060> 1 sip:192.168.2.3:5060 <http://192.168.2.3:5060> <http://192.168.2.3:5060>/ Am I missing some steps? Do I also need to configure dialplan or any other file at Kamailio load balancer? Or those two steps basically done it all for simple load balancing configuration? Thanks for your responses. these steps are ok if you do not deal with NAT. If yes, then things get a bit more complex, you need PATH support on load balancer, but AFAIK, Asterisk does not support it -- maybe I am wrong. Cheers, Daniel -- Daniel-Constantin Mierla http://www.asipto.com/