For a smooth connection between flights, it's important that you give yourself adequate time between your first flight's arrival and your next flight's departure. This time between flights is known as your minimum connection time, and it is needed to allow for security checks and any necessary terminal changes. The minimum connection time varies between airports and between airlines. Be sure to know and follow the minimum times you need to make your connections.
For flights arriving from the U.S. and other international locations, baggage must be claimed, then processed through Canada Customs at the first Canadian point of entry. Passengers must then re-check baggage with the connecting airline at the respective check-in counter or at the ongoing/connection desk outside the Customs area.
For a connecting flight to the U.S.A., baggage must be claimed, then processed through U.S. Customs and Immigration. For a connecting flight to an international destination, baggage can be checked through to the final destination in most cases; however, passengers should check with the airline.