When accessing Sage CRM via the Web Services API a user session needs to be created.
private WebService WS=new WebService();
private logonresult SID;
SID=WS.logon("wsuser","x3%b0H2");
WS.SessionHeaderValue = new SessionHeader();
WS.SessionHeaderValue.sessionId = SID.sessionid;
//
//do work here
//
WS.logoff(SID.sessionid);
This would return in an on-premise install of CRM a session id that was in the form 92391231117384.