Share those plans with the facilitators. Designate a troubleshooter at all sites who will deal with technical difficulties. You and the facilitator should not have to do this. Make sure the troubleshooter knows how to handle simple problems and who to call for help. Establish the call 20-30 minutes before the class or meeting is to start.
Most problems arise during the connection.
You should be able to solve most connection problems before the scheduled start. If the remote site can still hear you, explain the problem. If the other site cannot hear you, call them. Try to reconnect by hanging up and redialing. If the problem is too severe to correct quickly, have the remote site facilitator follow the contingency plan.