Simple SIP(VOIP) based phone in C#

IntroductionThis application was developed and is currently in use as "Help -> Call to support". The idea is to create zero configuration very simple call-out phone, thats how it is now.  (Though IP based incoming calls supported. Example To: sip:test@ip:7666, 7666 is the port SIP_Call out runs). Currently this application runs on windows only. For some reason .NET "still" has no managed support