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Semi-Technical
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Videoconference
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Videoconference
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As mentioned in the introduction to direct videoconferencing, only two parties can participate in a direct conference. If more people need to participate (for example, one county consulting two on-campus experts), each participant must connect to a reflector: another computer which manages the connections to send received video to everyone involved in the conference. The reflector acts something like a conference centre: it is a place for many people to meet and discuss. The overall network picture then looks like this:
The reflector that will be used for this project is the ISU Entomology reflector. There are six conferences, each for a different purpose. If the reflector is a conference center, then each conference is like a room in the center: different activities are happening in different rooms. Just finding the right "building" (reflector) isn't enough, you must also find the right "room" (conference) for your topic. Please use the conference that matches your topic.
Joining a conference is just like directly connecting to another person. First you must hang up on any direct conference that you are in, then you dial in to the reflector. Other people in the same conference will then appear, and you will be able to type and send video to all of them at one.
You do not need to do anything to set up the conference. They are all permanently active on the reflector. The Cu-SeeMe phonebook should have a 'Conferences' group in the pulldown menu at the top (see left). Double-clicking on any of the conferences will connect you to the reflector. Then, a screen will come up listing the various conferences on the reflector(right). The conference you selected from the dialing menu will be highlighted. All you have to do is click "Join." Do not worry about passwords; they will be filled in automatically based on which conference you selected from the dialing menu. Then, you will be connected and can participate in a three-way (or more!) conversation. Note that if you want to talk to someone else on the reflector, they must connect to the reflector themselves; you cannot 'call' someone 'through' the reflector. Remember: if you act as though the conference you are calling is a person, you will get through fine.
Using the reflector instead of a direct conference gives you:
- all of the advantages of direct videoconferencing
- plus the ability to have many people involved
- all of the limitations of direct conferencing, such as bandwidth and quality concerns
- quality seems to be marginally lower, and speed noticable slower (fewer frames per second) through the reflector than a direct connection. Mainly you will notice that motion seems 'choppier' and the initial image may be a little bizarre (embedded in green fog, for example). However, the image does clear up eventually. These effects are far more noticable with the Macintosh version of Cu-SeeMe. The reflector does not seem to give Macs as much time as PC's. Since most extension computers are PC-compatible, however, this should not be a major problem.
- if you wish to confer with someone on the reflector, they must be connected to the reflector and monitoring it. There is very little warning given when someone joins a conference on the reflector, whereas when you call someone direct, their computer 'rings' for awhile. Probably the best way to get someone's attention is to:
- check the reflector and see if someone is there that can answer your question
- direct dial the person you wish to talk to if they are not on the reflector
- once the connection is established, ask them to hang up and dial in to a conference on the reflector
