A.FXS
B.FSO
C.E&M
D.auxiliary port
E.802.3af ethernetports

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