All of these are fundamental building blocks of 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 remarking to complex policing and shaping
operations.
Packet classification – Packet 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 marking – Packet 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 management – Congestion 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 avoidance – Congestion 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.