Mitigating Performance Degradation in a Network Using FIFO Queuing for Data Backup with FTP

Effective Bandwidth Utilization Strategies for Network Performance Optimization

Question

FIFO queuing is being used on all routers in a network.

The primary application running on the network is data backup using FTP.

At certain times, users experience cyclical performance degradation.

What two things might mitigate this problem and help ensure bandwidth is used effectively in the network? (Choose two.)

Answers

Explanations

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A. B. C. D. E.

BD.

The problem described in the scenario is that cyclical performance degradation is being experienced by users during data backup using FTP. The usage of FIFO queuing on all routers in the network can be the reason for this problem because it provides equal access to all traffic, including low-priority traffic like FTP. To mitigate this problem and ensure effective use of network bandwidth, two solutions can be considered: traffic shaping and CB-WFQ.

  1. Traffic Shaping: Traffic shaping is a mechanism that allows the control of the traffic rate on an interface. It smooths out traffic bursts and ensures that traffic conforms to a particular rate limit. In this scenario, traffic shaping can be applied to the FTP traffic to limit its rate, thus freeing up bandwidth for other traffic. This will prevent FTP traffic from monopolizing the network, causing cyclical performance degradation.

  2. CB-WFQ: CB-WFQ (Class-Based Weighted Fair Queuing) is another mechanism that can be used to solve this problem. It provides a more refined method of queuing traffic than FIFO. CB-WFQ assigns a weight to each traffic class, and then it schedules packets for transmission based on the weight of the class they belong to. In this scenario, CB-WFQ can be configured to prioritize data backup traffic over other traffic, which will help ensure that bandwidth is used effectively.

The other options mentioned in the answer choices are not suitable for this scenario for the following reasons:

  • Traffic policing: Traffic policing drops or marks packets that exceed a certain rate limit, which may not be desirable for FTP traffic that needs to be transmitted. This may result in dropped packets and retransmission, leading to further degradation of performance.

  • WRED: WRED (Weighted Random Early Detection) is used to prevent network congestion by selectively dropping packets when the network is congested. In this scenario, WRED will not be useful as there is no congestion in the network.

  • MDRR: MDRR (Modified Deficit Round Robin) is a queuing mechanism used in MPLS networks. It is not applicable to this scenario, as no information is given about the use of MPLS in the network.