Making SIP work on Windows

Few months back I did some research on open source Windows based SIP stacks and the sheer number of options available excited me. We explored several stacks: SIPX, PJSIP, ReSIProcate. In this article and few others I will put down my insight into what we learned during an ordeal which lasted for six months, talking to numerous people, vendors and component providers. Our goal was to have a stable, clean and extendable SIP API in our application well integrated with some good quality sound processing software. That was just 50% of the application. The other 50% was to do with rich GUI and data processing functionality for supporting a SaaS application on Windows. Nothing like this existed in the market. Our application was also a smart SIP client which implemented some new Peer-2-Peer techniques to avoid expensive network components which were inscalable and hard to manage (and thus supported the SaaS based model very well).