Exam 200-301 topic 1 question 599 discussion

Key guidelines are Delay one way: 150ms or less Jitter: 30ms or less Loss: 1% or less From the official cert guide vol 2 Ch11.

I choose C, because for voice traffic, usually UDP is used at transport layer, and a little bit packet doesn't matter

Trick questions that are this close should be banned. Designed to make you fail.

C describes class-based differentiation of traffic. It can use various methods to achieve the expected results, such as low loss, low delay, low jitter etc. B is only talking about one aspect. Therefore C is a better option.

Option c is more logical

It´s B VoIP calls are sensitive to packet loss, as it can lead to gaps or degradation in voice quality. So QoS helps minimize packet loss by prioritizing the delivery of voice packets over less time-sensitive data. Also QoS enables the prioritization of critical traffic over less time-sensitive data. For example, voice and video traffic can be given higher priority to maintain call clarity and video quality. This ensures that essential services continue to function smoothly, even in the face of network congestion.

I'd say C

It´s C

It's a difficult one. B is true because QoS does indeed reduce packet loss for voice traffic since you can assign them to a priority class that minimizes their chance of being dropped such as using CoS 5 or DSCP EF markings. This means they're less likely to be dropped in times of congestion, or will be assigned to a higher priority queue in PQ/LLQ setups. However, the question asks about "optimization", and in that respect I lean toward C. Packet loss alone is only one of three important variables in voice traffic quality; the other two being jitter and delay. Differentiation of voice and video traffic facilitates optimization of all three of these criteria. Video traffic is bandwidth-intensive, and so differentiating it from voice traffic may involve placing voice traffic into a strict priority queue where it's sent from the interface immediately, thereby ensuring all three reliability and quality criteria are met for voice traffic.

Packet loss is acceptable that is why it uses udp and also uses platinum Qos

Don't think too much. the question is about QoS which can prioritize voice traffic over any other traffics. Please see the following article: https://www.nextiva.com/blog/voip-qos.html

Don't think too much. the question is about QoS which can prioritize voice traffic over any other traffics. Please see the following article: https://www.nextiva.com/blog/voip-qos.html

I think correct answer is C

A Prioritization Strategy for Data, Voice and Video: <omitted> 4. Put voice in a separate queue from video so that the policing function applies separately to each. <omitted> Source: CCNA 200-301 Official Cert Guide, Volume 2 (pg. 245)

The foundation of Qos is classificaiton.

I would go with B, as RoguePotatoe stated, voice traffic can only function with a 1% packet loss or less, so it makes sense to avoid packet loss. Besides that, since video and voice traffic are both traffic types that can't afford delays or packet loss, I don't see how differentiating them would help regarding voice traffic.

I'll go with B, since the question only talks about voice. Besides, if why stop at differentiate voice and video, why not data traffic as well?