If your flight originated in Canada and you need to take a connecting flight to an international destination, and you already have your boarding pass, you do not need to leave the restricted area or worry about your checked luggage.
You can confirm your departure gate number on one of the flight-schedule display screens and keep your boarding pass on hand to go through the control entry into the international area. Once in the international area, you can not return into the mixed area.
If, for any reason, you wish to leave the restricted area (before entering the international area), remember to have your boarding pass and passport with you and to present yourself sufficiently in advance at the security checkpoint for your departure.
If you do not have your boarding pass, you need to obtain one at your airline’s check-in counter.