Exam 200-301 topic 1 question 554 discussion

"Many popular QoS techniques that serve data traffic very well, such as WFQ and RED, are ineffective for voice applications." "FIFO (first-in, first-out). FIFO entails no concept of priority or classes of traffic. With FIFO, transmission of packets out the interface occurs in the order the packets arrive" thus D https://www.cisco.com/c/en/us/td/docs/ios/solutions_docs/qos_solutions/QoSVoIP/QoSVoIP.html https://www.cisco.com/c/en/us/td/docs/ios/qos/configuration/guide/12_2sr/qos_12_2sr_book/congstion_mgmt_oview.html enjoy

Given Answer : PQ Deciding Which Queueing Policy to Use •PQ guarantees strict priority in that it ensures that one type of traffic will be sent, possibly at the expense of all others. Strict PQ allows delay-sensitive data such as voice to be dequeued and sent before packets in other queues are dequeued. https://www.cisco.com/c/en/us/td/docs/ios/qos/configuration/guide/12_2sr/qos_12_2sr_book/congstion_mgmt_oview.html

D is c correct

With Priority Queueing (PQ), traffic is classified into high, medium, normal, and low priority queues. The high priority traffic is serviced first, then medium priority traffic, followed by normal and low priority traffic. -> Therefore we can assign higher priority for voice traffic. Therefore PQ is the right answer

Anyone studying the book that can point PQ out in book 2?

PQ almost always refers to voice as per https://www.cisco.com/c/en/us/td/docs/wireless/controller/7-4/configuration/guides/consolidated/b_cg74_CONSOLIDATED/b_cg74_CONSOLIDATED_chapter_01110.html

Yes, correct