Everything originates from NORAD and goes through Winnipeg. Under the region's command, you have the tactical control centre, the Canadian Air Defence Sector, which is located in North Bay, Ontario. The tactical intercept managers are in direct communication with the fighters and deal with in-flight fuel needs, if need be, depending on the duration of a mission. Consequently, things start out at NORAD and are relayed to the region and then to the sector.
On April 1st, 2009. See this statement in context.