Interoperability with Out-of-Band Collaboration Applications

Another aspect of supporting audio-only participants is providing a method for all participants to collaborate on shared documents and presentations. Cisco TelePresence provides for auxiliary video inputs and outputs so that users can attach their PCs to the system, and how that signal is encoded and multiplexed over RTP so that all the other TelePresence participants can see it. But how do the audio-only participants get to view it, and can the audio-only participants share a document or presentation with the TelePresence participants?

The predominant method of sharing documents and presentations on an audio conference is through the use of web-based collaboration tools such as Cisco MeetingPlace or Cisco Webex. There have been other methods in the past, such as the infamous T.120 protocol, but those are pretty much defunct. Therefore, the way forward is to engineer a method whereby the auxiliary video channel can automatically convert into a format viewable by the web conference participants and vice versa. At the time this book was written, this functionality was in the process of being developed.

In the meantime, there is a method for achieving the desired results, but it requires steps on the part of the user to enable it. It’s relatively simple but requires a three-step process:

Step 1	The user attaches his or her PC to the auxiliary (VGA) video input of the TelePresence system. This allows whatever he or she is sharing to be instantly viewed by all the other TelePresence participants.
Step 2	The user dials into the audio conferencing server and enters the appropriate DTMF tones to bridge the TelePresence meeting into the audio conference (as described in the previous sections).
Step 3	The user also fires up the web browser on his or her PC and logs onto the web conferencing server for that audio conference and joins the meeting as a web-participant as well and then activates the sharing feature within that web conference.

Now whatever the user shares on her PC is sent simultaneously by his or her PC over VGA to the Cisco TelePresence Primary codec and over HTTP to the web conference. Although this adds a degree of complexity to the ease-of-use of TelePresence, the good news is that it works with virtually any audio and web conferencing product on the planet.