Open source software packages typically have a hard time competing with commercial solutions. This is a perfect example of such a case. Commercial carrier-grade softswitches typically include HA, but FreeSWITCH (the best open-source alternative softswitch) does not have that functionality. You can use 3rd party programs like Pacemaker and Corosync to bridge the gap, but they are complicated and time consuming to correctly configure and test. It makes the whole solution feel "custom rolled" while most companies want something that feels "commercial". They want a "finished product," not something they need to bolt other pieces onto in order to get their desired features. If you are an entrepreneur, you will recognize the opportunity to take such sets of packages and roll them into your own "commercial" solution which you sell at a significant discount to other commercial solutions. However, this just propagates more commercialism. For those of us who want truly free, well-engineered solutions which feel "commercial", we are often just out of luck. So we turn to rolling our own. I started writing mod_ha_cluster for FreeSWITCH to help bridge this gap between an open source solution I feel could compete with very expensive commercial alternatives if it had such functionality and what's there today. If you are interested in VoIP in general or FreeSWITCH more specifically, please check out the project and help support it any way you are willing and able to do.