A.the time it takes for a Layer 3 switch or a router to switch a packet from an inbound interface to the queue of the outbound interface
B.the time it takes for a propagate from source to destination
C.the time it takes to place a frame on the physical medium for transport
D.the time a packet resides in the outbound queue of a router

A.delay sensitive packets are given preferential treatment
B.the default policy identifies a delay sensitive class and default class
C.the default policy identifies a delay sensitive class， best effort class， and default class
D.the model is highly scalable
E.the model is still predominant on the internet F the model provides guaranteed service