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When configuring AutoQoS VoIP on a Cisco Catalyst switch how is the configuration performed?
A. The auto qos voip command is applied to each interface.
B. The auto qos voip command is applied globally in the switch.
C. Each interface will need either the auto qos voip cisco-phone or auto qos voip trust on each interfacedepending on the upstream device.
D. Each interface will need either the auto qos voip trust cisco-phone or auto qos voip trust trust on eachinterface depending on the upstream device.
Correct Answer: C
Explanation/Reference:
Explanation: The QoS mechanisms on a Catalyst switch differ from those QoS mechanisms found on arouter. For example, while a router uses LLQ as a priority queuing strategy, a Catalyst switch might useweighted round-robin (WRR) as a priority queuing strategy. Fortunately, the AutoQoS feature available onsome Catalyst switch models applies voice-specific QoS features globally to a Catalyst switch and also atthe port level. To configure AutoQoS on supported Catalyst switch platforms, issue the following commandfrom interface configuration mode:
Switch(config-if)#auto qos voip [trust | cisco-phone] If the trust option is used in the previous command, theCatalyst switch makes queuing decisions based on Layer 2 Class of Service (CoS) markings. However, ifthe cisco-phone option is used, the Catalyst switch makes queuing decisions based on CoS markings originating from a Cisco IP phone. The switch detects the presence of a Cisco IP phone via the CDP. http://www.cisco.com/en/US/docs/ios/12_2t/12_2t15/feature/guide/ftautoq1.html
