I am interested in opinions and suggestions about load balancing with Kamailio.  I work for an ITSP that currently uses Oracle & Broadsoft, and I am working to design and develop an open source solution using Kamailio (Proxy, Registrar, LB) &  other Application/Media servers for more flexibility and freedom :)  Thank you ALL for the work you have put in on Kamailio!

After much reading and configuration I have a Kamailio 'proxy' setup, with endpoints registered using the Registrar module, and calls being sent/received to/from the PSTN. I am interested in separating the Load Balancers from the Registrars & logic, for security and in order to be able to scale appropriately.  I will be using the dispatcher module for both load balancers and proxies using the following architecture:

PublicIP = 5.5.5.5; Private IP = 192.168.1.0/24

USERS (Public Internet) ==> (public: 5.5.5.5)  [ Kamailio (LoadBalancer, Firewall, Sanity Checks) ] (core:192.168.1.2) ==> [ Kamailio Registrar, Proxy, PSTN GW ] ==> AppServers or PSTN GW

(we can access our PSTN gateways Via our Core using Private IPs)

Questions: 

1) Is it overkill to separate the LB & Proxy/Registrars?  

2) Is this a common architecture & anyone configured this architecture successfully? 

Thanks in advance for your help!