The Lincoln Concession Corporation is implementing a Cisco IP Videoconferencing solution that includes a Cisco CallManager and a Cisco IOS Gatekeeper. The customer uses H.323 and H.320 devices exclusively. Video calls will use RTP streams for audio, video, and far-end camera control and a sequence of call control signaling messages. What handles negotiation of the video codec (H.261, H.263), resolution, frame rate, and H.323 annexes?

A.
intercluster trunks

B.
Cisco CallManager

C.
Cisco MCM Gatekeeper

D.
Cisco IOS Alternate Gatekeeper

E.
video endpoints