I'm looking for a SIP/RTP implementation for C#, and I've stumbled upon MS "UCC API SDK", which looks promising at first glance. But googling it gives information mostly related to Lync, and dated around 2007-2008.
Is this technology alive? Should I try it or just let it rest in peace?
Also, is there a better (preferably open-source) solution for SIP/RTP client for .Net?