What kind of connection is used for VTC? Broadband? closed circuit? satellite uplink? or something else? What software is used to create and grade tests that are given over VTC? How many people can participate in a VTC at once?
You seem to be asking very contextual questions without providing the required context. Maybe some background?
You're wanting to use this for school? If you're enrolled at a university talk to the distance ed department and see if they have videoconferencing equipment on site you can use for a class. You can buy a Polycom ViaVideo unit that can connect to conferences through your computer. They run three to four hundred dollars though. Normally for tests you still have to show up for the test somewhere, whether it's where the class is actually originating from or at a local college that has agreed to proctor the test for you. Video quality can vary by day, especially if you're doing it out of your home over broadband or something similar. If you're on a campus and using their equipment that's hooked into Internet2, you can have very stable conferences. Commodity internet's more of a crapshoot, you never know how it's going to be routed from one day to the next and how the hops are going to be. One day it may be great, the next it may be spotty. You never know. If you have any more detailed questions post them, I'll see if I can't help you.
