Quality of Service (QoS) Management

Correct Answer: Class-Based Weighted Fair Queuing (CBWFQ)

The best method for managing VoIP traffic in a network using strict QoS policies is Class-Based Weighted Fair Queuing (CBWFQ). This technique classifies traffic into different classes and allocates bandwidth accordingly. It prioritizes certain types of traffic, such as VoIP, over less critical data to ensure that voice communication remains consistent and efficient. On the other hand, the Differentiated Services Code Point (DSCP) is mainly used for marking packets for different service levels, not specifically for managing VoIP traffic. Weighted Fair Queuing (WFQ) is a good algorithm for managing network traffic, but it is not as advanced or flexible as the CBWFQ in regards to VoIP traffic. Meanwhile, the Round Robin method is more suitable for environments where all traffic should be treated equally, which is not usually the case in network scenarios with VoIP services.

Correct Answer: Random Early Detection (RED)

Among all the provided answers, the best choice to reduce packet loss in a video streaming service is the Random Early Detection (RED). This mechanism is used to avoid network congestion by smartly discarding packets before the network becomes full. It calculates the average queue size and, based on this, it drops packets randomly, being more aggressive as the queue gets fuller. This prompts TCP-based processes to reduce their transmission rate and thus frees up bandwidth, preventing further packet lossNow let us explain why the other answers are not the best choices:- The Differentiated Services Code Point (DSCP) is a method for managing network traffic and is a field in an IP packet that enables different levels of service to be assigned to network traffic. It doesn't directly reduce packet loss, it's more about prioritizing certain types of traffic over others- First-In First-Out (FIFO) is a queuing strategy that functions exactly as its name suggests and processes packet in the order they arrive. FIFO does not do anything special to manage congestion and therefore does little to prevent packet loss- Round Robin is a strategy that assigns an equal fixed amount of time for each process. Round-Robin itself does not reduce packet loss, it's more about providing a fair distribution of resources.

Correct Answer: Resource Reservation Protocol (RSVP)

The best answer is 'Resource Reservation Protocol (RSVP)'. It allows applications to reserve a pre-determined amount of bandwidth on a network, ensuring quality of service for data transmission. This would be ideal for a company that wants to reserve bandwidth for video conferencing. The other options, such as 'Differentiated Services Code Point (DSCP)', 'First-In First-Out (FIFO)', and 'Weighted Fair Queuing (WFQ)', are also QoS technologies. However, they are more focused on prioritizing traffic rather than reserving bandwidth, which is required by the company in this scenario. Hence, they are not the best answers in this context.