Once the transmission error or lost data packets occurred in network flows

the terminal user might bring forward a new service requirement.Different with the traditional FCFS discipline

the strategy of feedback priority was proposed.The queue with this policy was analyzed by constructing a quasi birth-and-death process.Based on the spectral expansion method

the stationary distribution of queue length was obtained.Furthermore

the delay performances of the two queues with different feedback strategies were calculated

indicating that the strategy with feedback priority can improve the quality of service.