Exam 350-801 topic 1 question 209 discussion

This should be A, Video is typically variable bitrate

Suggestion: PLEASE Don't just answer by simply answering the question, provide your facts with relevant information, this way we can learn and understand from each other. A. Video is typically variable bit rate. https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/srnd/collab11/collab11/cac.html Video, on the other hand, has a variable bit rate (is bursty) and has a medium to large footprint when compared to audio, as well as a wide operational range of 1:40 (250p at 15 fps vs 1080p at 60 fps). Cisco Press Book CLCOR 350-801 p.320 Cisco strongly recommends that you direct only voice traffic to it because voice traffic is well behaved, whereas other types of real-time traffic are not. Moreover, voice traffic requires that delay be nonvariable in order to avoid jitter. Real-time traffic such as video could introduce variation in delay, thereby thwarting the steadiness of delay required for successful voice traffic transmission.

voice = EF and video = AF41 so can't be the answer B. It's A

Correct answer is A.

question asks by a characteristic of video traffic. Video traffic has following key characteristics: ■ Bandwidth: Variable bitrate (bursty) with medium/large footprint ■ Loss sensitive ■ Delay sensitive So, one of them is requested to answer the question, obviously is "Variable bitrate (bursty) with medium/large footprint", therefore it is easy enough, correct answer is A.

On the same link where the answer is provided by the admin is written: "The important point to keep in mind is that audio and video, while similar in transport and sensitivity to loss and delay, are quite different with regard to managing their bandwidth requirements in the network. It should also be noted that, while video is pertinent to a full collaboration experience, audio is critical. If, for example, video is lost during a video call due to a network outage or some other network related event, communication can continue provided that audio is not lost during this outage. This is a critical concept when thinking through the network requirements of a collaboration design such as QoS classification and marking." As so, voice and Video cannot have the same QoS requirements.

any comment please

A. B is not correct because voice and video have different QOS markings, voice=EF and video=AF41 or CS4

lets proceed by elimination: D is not correct ( Audio is a constant bit rate and has a smaller footprint compared to video, as well as a narrower operational range of 1:6 ratio when comparing the lowest bit-rate audio codec to one of the highest bit-rate codecs. Video, on the other hand, has a variable bit rate (is bursty) and has a medium to large footprint when compared to audio, as well as a wide operational range of 1:40 (250p at 15 fps vs 1080p at 60 fps). C is definitely not correct. B is not correct neither because. although Voice and video traffic are different is true, they DO NOT have the same QoS requirements. So this leave us with A as we all know that Video traffic is busty.

B. Correct as the question is about "What is a characteristic of video traffic that governs QoS requirements for video ?" not characteristics of video

Correct answer is A