Hello! I tried to get answer from implementors group and some other person, but I couldn't get any satisfiable answer. My question is here. In section 8.4.3.2(Figure 28/H.323-Non-MC invite signalling), when an endpoint(E1) which do not have active MC wants to invite other endpoint(E3), does E1 send an ARQ to its Gatekeeper for the invite or does E2 send the ARQ to its gatekeeper, or do both of them send ARQ's? And, when Gatekeeper doesn't know which endpoint has active MC in any conference, what should Gatekeeper do if it receives ARQ(for invitation) from an endpoint which do not have active MC? I mean, if Gatekeeper receives ARQ from E1, what should Gatekeeper do? Does Gatekeeper send ACR with E2's CallTransportAddress instead of E3's CallTransportAddress? Best wishes, soo. Nada Research Co., Ltd. Korea TEL : 82-2-525-3941 Lee Hyoung soo. mailto:soo@nada.co.kr