The teacher's machine in every classroom has Skype3.8 (free at skype.com), speakers, microphone and a free account such as PV321-prof, PV323-prof, etc. always on. Skype must be configured to auto-answer (Menu: tools/options/calls/advanced/automatically answer incoming calls)Reception has Skype running and can call any classroom by double clicking it's contact name. A call to a group of classrooms is instantly set-up by right clicking the group name and choosing "Start Conference Call". A group can be setup by dragging contacts to a group.
To use her telephone instead of a separate microphone, the receptionist could add her phone number to the group. Calling the group rings her phone as well as the group. Skype unlimited account required at $2,95 per month.
