Quality of Service (QoS)

Correct Answer: Delay optimization

Delay optimization is the most suitable quality of service (QoS) measure to solve issues related to network latency. It works to reduce lagging problems, particularly in video conferencing applications where communication in real-time is essential. Now, let's explain why the other options are not right for this scenario. Policing works to control the rate of traffic, but it doesn't help in reducing latency. Instead, excessive policing could add latency. Packet reassembly is more relevant in cases where packets are fragmented to align with the network's maximum transfer unit (MTU) sizes, not in minimizing latency. Lastly, error recovery is a method to correct errors that occur in the transmission, which does not directly impact latency. So, for the given case, delay optimization is the appropriate solution.

Correct Answer: Traffic policing

Traffic policing is the correct choice in this scenario as it allows administrators to limit traffic rates for certain types of data, in this case, non-business-related applications. This technique drops or marks packets that exceed the allocated bandwidth, and hence is useful in maintaining QoS (Quality of Service) in an organizational network. The other options are not as appropriate: DSCP (Differentiated Services Code Point) is used for traffic classification, not limiting; Weighted round-robin is a scheduling algorithm, not a bandwidth limiting technique; Token bucket is a method used to check that data transmissions, in the form of packets, conform to defined limits on bandwidth and burstiness (a measure of the unevenness or variations in the traffic flow), but it does not allow for the selective limitation needed here.

Correct Answer: Traffic shaping

Traffic shaping is the best QoS method to improve video streaming quality in the school's network. It can prioritize video traffic and ensure it gets the necessary bandwidth by controlling the rate at which packets are sent. This helps prevent video buffering and provides a smoother streaming experience. Policing enforces bandwidth limits but doesn't actively improve quality. Classification and marking only identify and tag traffic without actively managing it. Delay buffering is not a standard QoS mechanism for improving video streaming.