We know that restart of sip server hinders all ongoing traffic and slows development of routing logic. Due to limitation of customization with native language and mostly due to the fact that interpreter pre-compiles kamailio.cfg at startup preventing routing script to reload without restart, other programming languages were used such as Kamailio Embedded Interface (KEMI) framework. Post v5 of Kamailio , the interpreters of these languages were integrated with Kamailio and feature rich SIP routing logic could be written with them for runtime execution. The routing blocks are in form of functions written in a KEMI supported scripting language such as Lua as discussed in this article. Other components are still initialized by kamailio.cfg at startup. Apart from above mentioned advantages of programming languages , another plus point is that it enables test-cases , debug functionality without having to restart the server for code update.