Q.1 What does QoS stand for in networking?
Quality of Service
Quantity of Service
Queue of Service
Quick Operational Service
Explanation - QoS stands for Quality of Service, which refers to the overall performance of a network, particularly in terms of latency, jitter, and packet loss.
Correct answer is: Quality of Service
Q.2 Which QoS parameter measures the time taken for a packet to travel from source to destination?
Throughput
Latency
Jitter
Bandwidth
Explanation - Latency is the time it takes for a packet to travel across a network from source to destination.
Correct answer is: Latency
Q.3 Which of the following is NOT a typical QoS metric?
Bandwidth
Packet Loss
Latency
File Type
Explanation - File type is unrelated to QoS. QoS metrics typically include bandwidth, latency, jitter, and packet loss.
Correct answer is: File Type
Q.4 What does jitter refer to in QoS?
Variability in packet delay
Network throughput
Packet loss
CPU usage
Explanation - Jitter is the variation in packet delay over time and is important for real-time applications like VoIP.
Correct answer is: Variability in packet delay
Q.5 Which network application is most sensitive to packet loss?
Email
Web browsing
Video streaming
File transfer
Explanation - Video streaming is sensitive to packet loss because missing packets can cause visible glitches in the video.
Correct answer is: Video streaming
Q.6 Which QoS mechanism prioritizes certain types of traffic over others?
Traffic shaping
Routing
Traffic prioritization
Encryption
Explanation - Traffic prioritization ensures that high-priority traffic, such as voice or video, is transmitted before lower-priority traffic.
Correct answer is: Traffic prioritization
Q.7 What is the main purpose of traffic shaping?
Reduce latency
Control network traffic flow
Encrypt packets
Increase bandwidth
Explanation - Traffic shaping is used to control the amount and rate of traffic sent into the network to avoid congestion.
Correct answer is: Control network traffic flow
Q.8 Which layer of the OSI model typically implements QoS?
Physical
Data Link
Network
Application
Explanation - QoS mechanisms are often implemented at the Network layer, such as IP packet prioritization and scheduling.
Correct answer is: Network
Q.9 Which QoS technique delays lower priority traffic to ensure higher priority traffic gets through?
Packet dropping
Traffic policing
Traffic shaping
Flow control
Explanation - Traffic shaping delays packets of lower priority to smooth traffic flow and ensure high-priority traffic is delivered on time.
Correct answer is: Traffic shaping
Q.10 Which protocol is commonly used to signal QoS requirements for multimedia sessions?
HTTP
SMTP
RTP
RSVP
Explanation - RSVP (Resource Reservation Protocol) is used to reserve resources and signal QoS requirements for a network session.
Correct answer is: RSVP
Q.11 Which type of traffic would benefit most from low jitter?
VoIP calls
File downloads
Email
Web browsing
Explanation - VoIP calls are highly sensitive to jitter because inconsistent packet arrival times can degrade call quality.
Correct answer is: VoIP calls
Q.12 Which QoS strategy involves dropping packets when congestion occurs?
Traffic shaping
Traffic policing
Packet queuing
Admission control
Explanation - Traffic policing monitors the traffic rate and can drop packets that exceed the allowed rate to enforce QoS policies.
Correct answer is: Traffic policing
Q.13 In QoS, what is the effect of increasing bandwidth?
Reduces packet loss
Increases latency
Increases jitter
Decreases priority
Explanation - Increasing bandwidth reduces congestion and can lower packet loss, improving overall QoS.
Correct answer is: Reduces packet loss
Q.14 Which queuing method provides strict priority to certain traffic classes?
FIFO
Weighted Fair Queuing
Priority Queuing
Round Robin
Explanation - Priority Queuing always serves high-priority packets first, ensuring that critical traffic is delivered promptly.
Correct answer is: Priority Queuing
Q.15 What is the term for the maximum rate at which data can be transmitted over a network link?
Latency
Bandwidth
Throughput
Jitter
Explanation - Bandwidth is the maximum data transfer capacity of a network link, usually measured in bits per second.
Correct answer is: Bandwidth
Q.16 Which QoS service is best for real-time interactive traffic?
Best Effort
Guaranteed Service
Controlled Load
No Service
Explanation - Guaranteed Service provides guaranteed bandwidth and low latency for real-time applications like video conferencing.
Correct answer is: Guaranteed Service
Q.17 Which metric measures the percentage of packets lost during transmission?
Latency
Packet Loss
Jitter
Bandwidth
Explanation - Packet loss quantifies the fraction of packets that do not reach their destination, affecting QoS.
Correct answer is: Packet Loss
Q.18 Which of the following is a congestion control mechanism?
Traffic Shaping
Priority Queuing
Drop Tail
RSVP
Explanation - Drop Tail is a simple congestion control mechanism that drops incoming packets when the queue is full.
Correct answer is: Drop Tail
Q.19 Which QoS mechanism ensures that a data stream conforms to a specified traffic profile?
Traffic policing
Traffic shaping
Flow control
Packet scheduling
Explanation - Traffic policing checks the rate of traffic and can drop or mark packets that exceed the agreed profile.
Correct answer is: Traffic policing
Q.20 Which QoS model is commonly used in IP networks?
IntServ
DiffServ
MPLS
All of the above
Explanation - IntServ, DiffServ, and MPLS are all QoS models used in IP networks, each with different approaches to resource management.
Correct answer is: All of the above
Q.21 Which of the following describes Controlled Load service?
Provides guaranteed bandwidth
Offers service equivalent to lightly loaded network
Drops all excess traffic
No prioritization
Explanation - Controlled Load service attempts to provide performance similar to a lightly loaded network without strict guarantees.
Correct answer is: Offers service equivalent to lightly loaded network
Q.22 What is the effect of high jitter on streaming applications?
Smooth playback
Video freezing and glitches
Increased bandwidth
Lower latency
Explanation - High jitter causes packets to arrive at uneven intervals, leading to playback issues in streaming applications.
Correct answer is: Video freezing and glitches
Q.23 Which QoS scheduling technique allocates bandwidth based on weights assigned to different traffic classes?
FIFO
Weighted Fair Queuing
Priority Queuing
Random Early Detection
Explanation - Weighted Fair Queuing allocates bandwidth proportionally to different traffic classes according to assigned weights.
Correct answer is: Weighted Fair Queuing
Q.24 In DiffServ, which field in the IP header is used to indicate the QoS level?
DSCP
TTL
Protocol
Checksum
Explanation - DiffServ uses the DSCP (Differentiated Services Code Point) field in the IP header to mark packets for different QoS levels.
Correct answer is: DSCP