https://www.youtube.com/watch?v=BVUT4vM9eTk

OpenSIPS and Asterisk are a great combination to enable all sorts of SIP services. Starting from architectural level (like scalability, redundancy, geo-distribution), all the way up to to advanced services (like LCR, SIMPLE presence, call centers), OpenSIPS is the Asterisk companion. The typical OpenSIPS sandwich with Asterisk is the perfect combination of class 4a and class 5 SIP tools in order to achieve the ultimate platform.