Which ITU-T recommendation defines the procedures for using more than one video channel
in H.320- based systems?

A.
H.324

B.
H.230

C.
H.239

D.
H.264

E.
H.329

Explanation:
H:
239 is the ITU standard for a second video channel; this is supported by all the major
vendors, and is the only content channel standard supported by Cisco acquired Codian
products or Cisco TelePresence Serial Gateway Series products on H.323 video calls.Cisco
acquired Codian products need to be configured to enable H.239. Any H.323 endpoint that
also supports the
H:
239 protocol can source this channel, as can a VNC connection, though some endpoints
need to be configured to use H.239 instead of their proprietary solution.