Table of Contents
Question
Which undesired effect of increasing the jitter compensation buffer is true?
A. The overall transport delay decreases and quality improves.
B. The overall transport jitter increases and quality issues can occur.
C. The overall transport delay increases and quality issues can occur.
D. The overall transport jitter decreases and quality improves.
Answer
C. The overall transport delay increases and quality issues can occur.
Explanation
The correct answer to the question is C. The overall transport delay increases and quality issues can occur.
Jitter is the variation in the arrival times of packets in a network. It can occur due to network congestion, varying transmission delays, or other factors. To compensate for jitter, a jitter compensation buffer is often used. This buffer helps to smooth out the variation in packet arrival times, reducing the impact of jitter on the quality of the transmitted data.
However, increasing the size of the jitter compensation buffer can lead to certain undesired effects, including an increase in overall transport delay and potential quality issues. Here’s a detailed explanation of why this is the case:
- Overall Transport Delay: When the jitter compensation buffer is increased in size, packets are held in the buffer for a longer duration. This additional buffering introduces a delay in the transmission of packets. As a result, the overall transport delay increases, meaning it takes longer for packets to reach their destination. This increased delay can impact real-time applications such as voice or video, where low latency is crucial for maintaining quality.
- Quality Issues: The increased overall transport delay can lead to quality issues, particularly in real-time applications. Excessive delays can result in increased latency, which can cause noticeable issues such as audio or video distortion, synchronization problems, or interruptions in the communication. Applications that require real-time or interactive responses can be negatively affected by the increased delay, leading to degraded user experience.
The other options listed in the question are not accurate:
- Option A: The statement “The overall transport delay decreases and quality improves” is incorrect because increasing the jitter compensation buffer actually increases the overall transport delay, as explained above.
- Option B: The statement “The overall transport jitter increases and quality issues can occur” is also incorrect. The purpose of the jitter compensation buffer is to reduce the impact of jitter and stabilize the arrival times of packets. Therefore, increasing the buffer size does not increase the overall transport jitter.
- Option D: The statement “The overall transport jitter decreases and quality improves” is also incorrect. Increasing the jitter compensation buffer does not directly reduce jitter. It helps mitigate the effects of jitter by providing buffering, but it does not actively decrease the overall transport jitter.
In summary, when the jitter compensation buffer is increased in size, the overall transport delay increases, potentially leading to quality issues in real-time applications. It is important to strike a balance between compensating for jitter and maintaining an acceptable level of transport delay to ensure optimal quality of service.
Reference
- Compensation Buffer Sizing for Providing User-Level QoS Guarantee of Media Flows | IEEE Conference Publication | IEEE Xplore
- Understanding Jitter in Packet Voice Networks (Cisco IOS Platforms) – Cisco
- How to Use Jitter Buffers on TDMoP Products to Compensate for Packet-Delay Variation (PDV) | Analog Devices
Cisco Certified Design Expert CCDE v3.0 400-007 certification exam practice question and answer (Q&A) dump with detail explanation and reference available free, helpful to pass the Cisco Certified Design Expert CCDE v3.0 400-007 exam and earn Cisco Certified Design Expert CCDE v3.0 400-007 certification.