Live Communication Server, SIP, RTCCORELib

Question

Hello all. Would be grateful if you could help. At present, I'm writing a RTC based Client application so that it can talk/or connect to a Live Communication Server also known as a SIP server. The purpose is to check whether a particular user is logged on and if so take whatever appropriate action e.g send a message. I have already downloaded the relevant api which is the RTCCORELib which is contained in a "rtcdll.dll" file. I know that it contains the main class RTCClientClass which has to be initialised. Now my question is how would you connect to the SIP server and what parameters would be required to make the connection to that server? What classes and methods would be appropriate? Your co-operation would be highly appreciated. Thanks.