All of these are fundamental building blocks of a differentiated services Traffic Conditioner Block except which one?
A.
dropper
B.
classifier
C.
marker
D.
querier
E.
meter
F.
shaper
Explanation:
Differentiated Services Components
The following components make up the foundation of a Cisco Differentiated Services implementation:
Traffic conditioning (traffic policing and traffic shaping)Traffic conditioning is performed at the
edges of a DiffServ domain. Traffic conditioners perform traffic shaping and policing functions to
ensure that traffic entering the DiffServ domain conforms to the rules specified by the Traffic
Conditioning Agreement (TCA) and complies with the service provisioning policy of the domain.
Traffic conditioning may range from simple code point re-marking to complex policing and shaping
operations.
Packet classificationPacket classification uses a traffic descriptor (for example, the DSCP) to
categorize a packet within a specific group in order to define that packet. After the packet has been
defined (that is, classified), the packet is accessible for QoS handling on the network.
Using packet classification, you can partition network traffic into multiple priority levels or classes
of service. When traffic descriptors are used to classify traffic, the source agrees to adhere to the
contracted terms and the network promises a QoS. Traffic policers and traffic shapers use the traffic
descriptor of the packet (that is, the classification of the packet) to ensure adherence to that
agreement.
Packet markingPacket marking is related to packet classification. Packet marking allows you to
classify a packet based on a specific traffic descriptor (such as the DSCP value). This classification
can then be used to apply user-defined differentiated services to the packet and to associate a packet
with a local QoS group.
Associating a packet with a local QoS group allows users to associate a group ID with a packet. The
group ID can be used to classify packets into QoS groups based on prefix, autonomous system, and
community string. A user can set up to 64 DSCP values and 100 QoS group markings.
Congestion managementCongestion management (or scheduling) is achieved through traffic
scheduling and traffic queueing. When there is network congestion, a scheduling mechanism such
as CBWFQ is used to provide guaranteed bandwidth to the different classes of traffic.
Congestion avoidanceCongestion avoidance techniques monitor network traffic loads in an effort
to anticipate and avoid congestion at common network bottlenecks. Congestion avoidance is
achieved through packet dropping. Among the more commonly used congestion avoidance
mechanisms is WRED.
With WRED and Differentiated Services, you have the option of allowing WRED to use the DSCP
value when WRED calculates the drop probability of a packet.