What are the PHBs that DiffServ use?
A. resource reservation and admission control
B. default, AF, and EF PHBs
C. AF, EF, and CS PHBs
D. AF and EF PHBs
E. default, AF, EF, and CS PHBs
Correct Answer: E
Explanation/Reference:
Explanation: A Per Hop Behavior refers to the packet scheduling, queuing, policing, or shaping behavior ofa node on any given packet belonging to a Behavior Aggregate, and as configured by a Service LevelAgreement (SLA) or policy. To date, four standard PHBs are available to construct a DiffServ-enablednetwork and achieve coarse-grained, end-to-end CoS and QoS: The Default PHB, Class-Selector PHBs,Expedited Forwarding PHB and Assured Forwarding PHB.
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