In one embodiment, a system includes first and second gateway devices operable to communicate with respective first and second video terminals in accordance with H.323, the first and second gateway devices also being operable to communicate with each other over an H.320 call leg. Responsive to a first message received from the first video terminal that contains a terminal capability in H.245, the first gateway mapping the terminal capability into a non-standard section of an H.221 data stream, and send the data stream to the second gateway device. The second gateway device decoding the terminal capability from the non-standard section, encoding the terminal capability in H.245 in a second message, and sending the second message to the second video terminal. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure.