A method and system for dynamically triggering flow-based quality of service shortcuts through a router is disclosed. The method further includes the steps of receiving a data packet at a router, determining whether a shortcut has been set up for a data flow to which said packet belongs, checking the status of an onset trigger counter when no shortcut exists, and when a current value of said onset trigger exceeds an onset trigger value, setting up a new shortcut for said data packet belonging to said data flow. The method of the present invention includes a dynamic system for adjusting state variable to control the number of shortcuts in existence and the adjusting the shortcut set up rate for optimal router switching efficiency.