After the value of a conference’s Stateproperty is set to Connected, the application can invite new participants into the instant message conference using the BeginInviteRemoteParticipantsmethod, as demonstrated in the following code example.

Copy Code 
List<string> myTargets = new List<string>(2);
myTargets.Add(new string(“sip:john@contoso.com”));
myTargets.Add(new string(“sip:cathy@contoso.com”));
ToastMessage toastMessage = new ToastMessage(“Please join this team
meeting”);
conferenceSession.BeginInviteRemoteParticipants(myTargets,
toastMessage, Conference_InviteRemoteParticipantsCompleted,
conferenceSession);