Which three mechanisms are required to deploy QoS on an IP WAN? (Choose three.)
A.
queuing and scheduling
B.
Call Admission Control
C.
traffic shaping
D.
link efficiency techniques
E.
traffic classification
F.
bandwidth provisioning
Explanation:
Queuing, Traffic Shaping, and Policing
Cisco has developed many different QoS mechanisms, such as queuing, policing, and traffic shaping, to enable network operators to manage and prioritize the traffic flowing on the network. Applications that are delay sensitive, such as VoIP, require special treatment to ensure proper application functionality. Queuing refers to the buffering process used by routers and switching when they receive traffic faster than can be transmitted. Different queuing mechanisms can be implemented to influence the order in which the different queues are serviced (that is, how different types of traffic are emptied from the queues). Table 6-6 identifies QoS considerations to optimize bandwidth.
Cisco Press CCDA 640-864 Official Certification Guide Fourth Edition, Chapter 6
Shouldn’t the answer be A, C, D?
Looking at here: http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/srnd/4x/42nstrct.html#wp1043960
The following sections highlight some of the most important features and techniques to consider when designing a WAN to support both voice and data traffic:
•Traffic Prioritization
•Link Efficiency Techniques
•Traffic Shaping
Traffic Prioritization =/= Traffic Classification
Quote from the student guide:
“In addition to providing adequate bandwidth for all required applications, traffic classification, and voice priority queuing and scheduling, the WAN infrastructure typically requires additional mechanisms such as traffic shaping, link efficiency techniques an CAC.”
This statement means a normal QoS deployment for any network requires A, E and F but for a WAN network you also need B, C and D. The answer to the question must be B,C and D since it is specifically stating it is for a WAN.