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
Explanation:
A Per Hop Behavior refers to the packet scheduling, queuing, policing, or shaping behavior of a node on any given packet belonging to a Behavior Aggregate, and as configured by a Service Level Agreement (SLA) or policy. To date, four standard PHBs are available to construct a DiffServ-enabled network and achieve coarse-grained, end-to-end CoS and QoS: The Default PHB, Class-Selector PHBs, Expedited Forwarding PHB and Assured Forwarding PHB.
http://www.cisco.com/en/US/technologies/tk543/tk766/technologies_white_paper09186a00800a3e 2f_ps6610_Products_White_Paper.html