Which two scenarios would benefit the user the most by adding quality of service (QoS) to the network? (Choose two.)
- A student is communicating via Skype with a friend in another country.
- Students are updating information about their sport activities on the class Facebook page.
- A student is sending emails to a friend.
- Students are watching a lecture from a YouTube site.
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Scenarios That Would Benefit the Most by Adding Quality of Service (QoS) to the Network
In today’s digital environment, where a variety of applications compete for limited network bandwidth, Quality of Service (QoS) plays a critical role in managing and prioritizing traffic. QoS is a set of technologies used on a network to ensure the performance of high-priority applications, especially those sensitive to delays, jitter, and packet loss.
Given the four scenarios below:
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A student is communicating via Skype with a friend in another country.
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Students are updating information about their sport activities on the class Facebook page.
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A student is sending emails to a friend.
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Students are watching a lecture from a YouTube site.
The two scenarios that would benefit the most from QoS are:
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✅ A student is communicating via Skype with a friend in another country.
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✅ Students are watching a lecture from a YouTube site.
Let’s examine each scenario in detail to understand why QoS is crucial for some, and not necessary for others.
✅ 1. A Student is Communicating via Skype with a Friend in Another Country
Skype is a real-time communication application that uses Voice over IP (VoIP) and video streaming protocols. These types of applications are highly sensitive to network conditions such as:
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Latency (delay): This is the time it takes for a packet of data to travel from source to destination. For a VoIP call, even a delay over 150 milliseconds can become noticeable and degrade the conversation.
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Jitter: This refers to variation in packet arrival times. Inconsistent delivery of packets can cause choppy audio and video, making communication frustrating.
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Packet loss: Losing even a few packets in a VoIP conversation can significantly reduce the quality of the call.
How QoS Helps
With QoS, network devices such as routers and switches can prioritize VoIP traffic over less sensitive data such as file downloads or emails. This means:
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Voice packets are given high priority.
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The system can reserve bandwidth for Skype to maintain consistent call quality.
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QoS policies can reduce jitter and packet loss by ensuring packets are processed in the correct order and without delay.
Real-World Example
Imagine a student making an international Skype call while someone else on the same network starts a large file download or uploads a video. Without QoS, the Skype call may stutter or disconnect due to bandwidth competition. With QoS, the call would remain clear and uninterrupted.
✅ 2. Students are Watching a Lecture from a YouTube Site
Streaming video content, such as online lectures from YouTube, is another bandwidth-intensive activity that can benefit from QoS, especially in a shared or constrained network environment.
While YouTube is not as latency-sensitive as VoIP, it still requires:
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Consistent bandwidth: To avoid buffering or downgrading the video quality.
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Minimal packet loss: For maintaining continuous streaming without interruptions.
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Prioritization over background tasks: When multiple students are online, lectures should not be disrupted by less important traffic.
How QoS Helps
With QoS policies in place:
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Streaming traffic can be classified and prioritized over non-essential services like background updates.
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Buffering is minimized, ensuring smooth playback.
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QoS can dynamically allocate more bandwidth to video streams during peak times.
Real-World Example
Imagine a class of students watching a live lecture on YouTube while other users are downloading games or uploading large files to cloud storage. Without QoS, the lecture might buffer frequently, causing frustration and loss of information. With QoS, the educational content is prioritized, ensuring a seamless learning experience.
❌ 3. Students are Updating Information About Their Sport Activities on the Class Facebook Page
This scenario involves web browsing and social media interaction, which are not time-sensitive.
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Latency-insensitive: A small delay while posting on Facebook is usually not noticeable.
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Not continuous: Unlike streaming or VoIP, posting a status or picture is a brief, infrequent task.
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Can tolerate delay: Even if the upload is slightly delayed, it doesn’t degrade the user experience significantly.
Why QoS Is Not Critical
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Social media interactions do not require real-time delivery.
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QoS for such traffic is not essential and could be classified as “best-effort” traffic.
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Prioritizing this traffic would be wasteful and could negatively impact more critical applications.
❌ 4. A Student is Sending Emails to a Friend
Sending emails is one of the least demanding tasks in terms of network resources.
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Very low bandwidth requirement: Emails are typically small in size and require minimal data transfer.
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Not time-sensitive: Delays of a few seconds or even minutes generally don’t affect the user experience.
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Can be queued: Email systems are designed to retry delivery if a connection is slow or temporarily unavailable.
Why QoS Is Not Critical
QoS provides no real advantage here. Whether an email takes 1 second or 10 seconds to send is irrelevant in most cases. Such traffic is typically marked as low priority and does not need reserved bandwidth or jitter control.
Summary Table
| Scenario | QoS Required? | Reason |
|---|---|---|
| A student is communicating via Skype | ✅ Yes | Real-time voice/video, sensitive to latency, jitter, and packet loss |
| Students are watching a lecture on YouTube | ✅ Yes | Bandwidth-intensive, requires continuous data stream without buffering |
| Students updating sport activities on Facebook | ❌ No | Not real-time, can tolerate delay, low bandwidth |
| A student sending emails to a friend | ❌ No | Delay-tolerant, small data size, not time-sensitive |
Conclusion
Quality of Service (QoS) is a powerful mechanism to improve network performance by ensuring that critical, real-time, and high-priority applications receive the necessary resources to function effectively. Among the four scenarios provided, the Skype communication and YouTube lecture streaming stand out as activities that are either real-time or require high, consistent bandwidth. These applications are significantly affected by latency, jitter, and packet loss — making them prime candidates for QoS implementation.
On the other hand, tasks such as posting on Facebook or sending emails are delay-tolerant and low priority, meaning they do not benefit meaningfully from QoS.
By applying QoS effectively, network administrators can enhance user experience, especially in educational and professional settings where uninterrupted communication and media delivery are vital.