A、FIFO queuing， which provides a means to hold packets while they are waiting to exit an interface

B、Priority queuing， which ensures a fixed amount of bandwidth

C、Custom queuing （CO）， which provides a queuing tool that services all queues， even during times of congestion

D、Bandwidth queuing， which ensures a minimum amount of bandwidth

E、Weighted fair queuing （WFO）， which classifies packets based on flows