WorksheetsCPSC Exam review
Total questions: 99
Worksheet time: 1hrs 14mins
Which of the following statements best describes the “nuts and bolts” view of the Internet?
The Internet is an infrastructure providing programming interfaces to applications.
The Internet consists of interconnected end systems and packet switches, using links of varying transmission rates.
The Internet is a virtual space for application developers to test network theories.
The Internet guarantees end-to-end connection for reliable communication.
A user experiences significant queuing delays during online gaming. Which factor is most likely the cause?
Low transmission rate of the link.
High propagation delay due to distance.
Traffic intensity exceeding the outgoing transmission rate.
Use of guided media instead of unguided media.
Which protocol layer is responsible for routing packets from the source to the destination across the Internet?
Data Link Layer
Transport Layer
Network Layer
Application Layer
Which layer of the OSI model is responsible for encoding, encrypting, and compressing data for transmission?
Application Layer
Transport Layer
Session Layer
Presentation Layer
What is a primary advantage of the Peer-to-Peer (P2P) application architecture over the Client-Server architecture?
It provides better security for data transmission.
It does not require a permanent server, allowing for self-scalability.
It ensures 100% data integrity during transmission.
It minimizes latency by using a dedicated server.
Why is the "single mega-server" approach unsuitable for large-scale video streaming platforms like Netflix?
It creates a single point of failure and network congestion.
It lacks support for the DASH protocol.
It cannot handle variable bit-rate (VBR) encoded video streams effectively.
It requires storing videos at multiple distributed locations.
What is the primary reason for using Content Delivery Networks (CDNs) in video streaming?
To centralize all video content for easier management.
To ensure low-latency delivery of video streams by storing copies at multiple geographically distributed sites.
To provide constant bit-rate encoding for all video streams.
To reduce the need for adaptive streaming protocols like DASH.
In the transport layer, what is the main difference between TCP and UDP?
TCP uses a two-tuple for connection identification, while UDP uses a four-tuple.
UDP provides reliable data transfer with flow control, whereas TCP does not.
TCP ensures reliable, in-order delivery, while UDP offers unreliable, connectionless service.
Both TCP and UDP guarantee delivery but differ in congestion control mechanisms.
Why does the User Datagram Protocol (UDP) lack congestion control mechanisms?
It is designed to prioritize error detection over congestion control.
It operates independently of the transport layer and cannot manage network resources.
It is intended for applications that tolerate loss and prioritize speed, like DNS or video streaming.
It relies on the network layer to manage congestion.
If a transport-layer segment is received with a corrupted checksum, what typically happens?
The segment is delivered to the application layer with a warning.
The segment is discarded, and a retransmission is requested.
The segment is corrected using error-correction codes.
The segment is forwarded to the next hop without modification.
For which type of application is UDP more suitable than TCP?
A. Online banking that requires secure and reliable data transfer.
B. Real-time multiplayer gaming that needs low latency and can tolerate some packet loss.
C. Email communication where data integrity is crucial.
D. File transfer applications requiring in-order delivery of all packets.
What problem does the stop-and-wait protocol encounter when acknowledgments (ACKs) are corrupted?
A. The receiver cannot determine the correct sequence number.
B. The sender retransmits the packet, potentially causing duplicates.
C. The protocol halts due to the lack of feedback.
D. The channel automatically corrects the error.
How does the Go-Back-N protocol handle packet loss?
A. Retransmits only the lost packet.
B. Buffers the lost packet at the receiver until it is retransmitted.
C. Retransmits all packets starting from the last unacknowledged packet.
D. Does not handle packet loss and continues transmitting.
In Selective Repeat, what happens when an out-of-order packet is received?
A. It is discarded immediately.
B. It is buffered until missing packets are received.
C. The sender retransmits all unacknowledged packets.
D. The receiver requests a retransmission of the missing packet.
In a pipelined protocol with a window size of 4, what is the behavior if packet 2 times out in Selective Repeat?
A. The sender retransmits all packets in the window.
B. The sender retransmits only packet 2.
C. The sender closes the connection and restarts the session.
D. The receiver discards all packets after packet 2.
What is the primary function of the data plane in the network layer?
(a)
In a traditional network control plane, where are routing decisions made?
Within individual routers based on local algorithms.
At a centralized SDN controller.
In a cloud-based orchestration service.
At the source host before transmitting data.
Which of the following is a defining characteristic of Software-Defined Networking (SDN)?
Data plane decisions are made at individual routers.
Control plane logic is decentralized and implemented within each network device.
The control plane is logically centralized, enabling programmatic network management.
Routing is performed using traditional algorithms without abstraction.
What is the primary benefit of the programmability feature in SDN?
It minimizes the need for hardware redundancy in the network.
It allows for automated and customizable network functions via APIs.
It ensures that network devices can operate independently.
It eliminates the need for a physical control plane in routers.
Which analogy best describes the interaction between SDN controllers and network devices?
A traditional home with devices operating independently.
A factory where every machine operates without centralized instructions.
A smart home system where a central hub controls all connected devices via an app.
A library where patrons browse and select books without assistance.
What is the main advantage of using crossbar switching fabric in a router?
It reduces latency.
It increases bandwidth.
It simplifies network design.
It enhances security.
How does priority scheduling decide which packet to transmit next?
It transmits packets in the order they arrive.
It transmits the packet with the highest priority based on predefined criteria.
It transmits packets randomly from the queue.
It transmits packets from the shortest queue.
What happens if the Time-to-Live (TTL) field of an IP datagram reaches zero?
The packet is forwarded to the next router without changes.
The datagram is discarded to prevent indefinite circulation.
The TTL is reset to its maximum value and sent to the destination.
The header checksum is recalculated to adjust the TTL field.
Which scheduling policy ensures that each queue gets a proportional share of service based on weights?
First-In-First-Out (FIFO)
Priority Scheduling
Tail Drop
Weighted Fair Queuing (WFQ)
Why is IP fragmentation necessary in a network?
To allow routers to reassemble packets during transmission.
To enable large IP datagrams to traverse links with smaller MTUs.
To optimize transmission speed across all network links.
To reduce header overhead in datagrams.
What does the subnet mask /24 represent in an IP address?
The number of hosts allowed within a subnet.
The length of the subnet portion, leaving 24 bits for the host part.
The length of the subnet portion, leaving 8 bits for the host part.
The total number of subnets within the address space.
How does IPv6 improve over IPv4 in terms of header processing?
By using variable-length headers for flexibility.
By removing fragmentation and checksum fields to speed up processing.
What is the purpose of tunneling during the IPv4-to-IPv6 transition?
To encapsulate IPv6 datagrams within IPv4 headers for transport across IPv4 networks.
To convert IPv4 headers into IPv6 headers dynamically.
To fragment IPv6 datagrams into smaller IPv4 packets.
To allocate IPv6 addresses within an IPv4 network.
Which algorithm is commonly used in Open Shortest Path First (OSPF) for route computation?
Bellman-Ford
Prim’s algorithm
Kruskal’s algorithm
Dijkstra’s algorithm
What is the primary benefit of Software-Defined Networking (SDN) using a logically centralized control plane?
It eliminates the need for distributed routing algorithms.
It allows easier network management and flexible traffic flow control.
It removes the requirement for physical switches in the data plane.
It decentralizes the control logic to improve fault tolerance.
In the context of SDN, what is the purpose of the southbound API?
To define control functions for network control applications.
To allow communication between the SDN controller and data-plane switches.
To interact with external network monitoring tools.
To implement routing algorithms at the control plane level.
What is the primary purpose of Dijkstra's algorithm?
To find the shortest path from a starting node to all other nodes in a weighted graph.
To calculate the minimum spanning tree of a graph.
To identify all paths between two nodes in an unweighted graph.
To perform depth-first traversal of a graph.
In a weighted graph, what do the weights between nodes typically represent?
The number of nodes in the graph.
The cost or distance associated with the edge.
The degree of the nodes.
The number of edges in the graph.
The degree of connectivity between nodes.
The degree of connectivity between nodes.
The cost, distance, or time required to traverse between nodes.
The number of paths leading to a particular node.
The order in which nodes are visited during traversal.
Which real-world application is most likely to use Dijkstra’s algorithm?
Determining the optimal sequence for sorting data.
Routing data packets through a network to minimize latency.
Compressing images in multimedia files.
Encrypting data for secure transmission.
Why is Dijkstra's algorithm considered a "greedy algorithm"?
It makes decisions based on the smallest edge weight available at each step.
It finds all possible paths in the graph simultaneously.
It prioritizes nodes that are farthest from the starting node.
It guarantees the global optimal solution by exploring all options.
Imagine a drone navigating an urban area using Dijkstra's algorithm. What would the graph nodes and edges most likely represent?
Nodes represent drone waypoints; edges represent travel time or distance between waypoints.
Nodes represent battery levels; edges represent recharging stations.
Nodes represent GPS coordinates; edges represent altitude changes.
Nodes represent obstacles; edges represent safety ratings.
What is the primary responsibility of the link layer in a network?
Delivering datagrams from source to destination across multiple hops.
Transferring datagrams between physically adjacent nodes over a link.
Managing end-to-end connections between application processes.
Routing packets across different networks in the Internet.
What are MAC addresses used for in the link layer?
To identify devices within a subnet for routing decisions.
To determine network paths for data transmission.
To encrypt frames for secure communication over a link.
To uniquely identify devices in a shared medium for frame delivery.
What is the purpose of error detection and correction codes (EDC) in the link layer?
To compress data for faster transmission over a link.
To detect and correct bit errors caused by noise or attenuation.
To prevent unauthorized devices from accessing the network.
To prioritize certain types of traffic over others.
Which of the following is NOT a type of multiple access protocol?
Channel partitioning protocols
Random access protocols
Error detection protocols
Taking turns protocols
In Time Division Multiple Access (TDMA), how is channel access managed?
By dividing the channel into separate frequency bands for each station.
By assigning fixed-length time slots to stations in a round-robin manner.
By allowing multiple nodes to transmit simultaneously without coordination.
By polling each station to request transmission.
What is the key limitation of CSMA in wireless networks?
The lack of support for multiple access on the same channel.
The high overhead caused by token passing between nodes.
The requirement for a central coordinator to manage transmissions.
The inability to detect collisions due to strong local signal interference.
How does CSMA/CD improve upon basic CSMA?
By partitioning the channel into fixed time slots.
By reducing collisions using collision detection and aborting colliding transmissions.
By assigning unique tokens to each node to avoid conflicts.
By using frequency bands to separate transmissions from different nodes.
Which type of MAC protocol seeks to balance efficiency during both high and low traffic loads?
Channel partitioning protocols
Random access protocols
Taking turns protocols
In a polling-based "taking turns" protocol, what is a potential disadvantage?
Collisions between multiple nodes attempting to transmit simultaneously.
Idle slots when no station has data to send.
Single point of failure at the master node.
Inefficiency during low traffic loads due to token overhead.
What is the primary purpose of the Address Resolution Protocol (ARP)?
To assign IP addresses to devices in a network dynamically.
To map an IP address to its corresponding MAC address in the same network.
To establish connections between devices in different subnets.
To route packets from source to destination over multiple hops.
How is a MAC address different from an IP address?
MAC addresses are hierarchical, while IP addresses are flat.
MAC addresses are assigned by software, while IP addresses are assigned by hardware.
MAC addresses are used locally within the same network, while IP addresses are used globally for routing.
MAC addresses are temporary, while IP addresses are permanent.
What happens when a node wants to send a frame to another node but does not know its MAC address?
The node sends an ICMP request to resolve the address.
The node broadcasts an ARP query packet containing the target’s IP address.
The node sends a unicast request to the network administrator.
The node forwards the frame to the switch, which resolves the address.
Why is Ethernet considered an unreliable and connectionless protocol?
It uses slotted CSMA/CD for channel access.
It supports only single-path transmission.
It requires handshaking before data transmission.
It does not perform error correction or retransmission of dropped frames.
What is the role of a switch in an Ethernet LAN?
To assign IP addresses to devices.
To route packets between different networks.
To forward frames based on MAC addresses.
To perform error correction on frames.
How does a switch "learn" which hosts can be reached through its interfaces?
It consults a centralized server for MAC-to-port mappings.
It broadcasts frames and records the responses in its switch table.
It observes the source MAC address of incoming frames and records the interface.
It uses ARP to build a table of MAC addresses and their corresponding interfaces.
How do self-learning switches forward frames in a multi-switch environment?
They use preconfigured forwarding tables for all connected switches.
They rely on ARP to resolve destination MAC addresses.
They use the same self-learning mechanism as single switches to build forwarding tables.
They broadcast all frames to every connected switch.
What is a key difference between switches and routers?
Switches operate at the network layer, while routers operate at the data link layer.
Switches use MAC addresses to forward frames, while routers use IP addresses.
Routers store frames temporarily, while switches drop them if there is congestion.
Routers handle broadcast traffic, while switches do not.
What is the primary purpose of VLANs (Virtual Local Area Networks)?
To improve physical network performance by creating separate physical networks.
To isolate traffic within specific groups of devices for security and efficiency.
To prioritize traffic based on MAC address identifiers.
To reduce the need for MAC address learning in switches.
What role does a trunk port play in VLANs spanning multiple switches?
To provide a physical network appearance by creating separate physical networks.
To isolate traffic for MAC table reduction for security and efficiency.
To carry traffic for multiple VLANs between switches.
To prioritize traffic based on MAC address identifiers.
How does Multiprotocol Label Switching (MPLS) differ from traditional IP routing?
MPLS relies solely on destination addresses, while IP routing uses both source and destination addresses.
MPLS uses fixed-length labels for fast lookups, whereas IP routing uses variable-length prefix matching.
MPLS supports only connectionless traffic, while IP routing supports connection-oriented traffic.
MPLS replaces IP addresses in the datagram header for routing decisions.
What is the function of a load balancer in a data center network?
To replace routers in managing IP routing within the data center.
To handle all data link layer traffic among servers in a rack.
To distribute client requests across multiple servers for load balancing and efficiency.
To ensure MAC address mapping across different VLANs.
What is the role of the SDN controller in a logically centralized control plane?
It forwards data packets between routers and switches.
It computes and distributes flow tables to network devices.
It establishes direct communication between end hosts.
It handles error correction in transmitted frames.
Which of the following describes the concept of a subnet?
A subset of IP addresses grouped to reduce network congestion.
A virtual connection established between routers.
A division of a network address space into smaller, more efficient units.
A method for encapsulating Ethernet frames within IP packets.
In the context of NAT, why do all outgoing datagrams have the same source IP address?
To simplify routing within the internal network.
To conserve IP addresses by using one public IP for all devices.
To anonymize all devices in the network for security reasons.
In a 2D parity error detection scheme, which of the following identifies the location of a single bit error?
A. The row and column where parity mismatches occur.
B. The first row containing a parity bit mismatch.
C. The checksum computed from the data field.
D. The cyclic redundancy check (CRC) value.
How does a memory-based switching fabric work in first-generation routers?
A. Packets are forwarded directly without copying into memory.
B. The CPU manages all forwarding by reading and writing packets in system memory.
C. Packets are switched using fixed-length labels for faster lookup.
D. A crossbar mechanism interconnects input and output buffers directly.
What is one key advantage of IPv6 over IPv4?
A. IPv6 supports hierarchical addressing, while IPv4 does not.
B. IPv6 eliminates the need for NAT by offering a larger address space.
C. IPv6 does not support fragmentation, unlike IPv4.
D. IPv6 uses 32-bit addresses, offering backward compatibility.
What is the primary function of the physical layer in the OSI model?
A. To establish end-to-end communication between devices.
B. To transmit raw bitstreams over a physical medium.
C. To manage error detection and correction in transmitted data.
D. To determine the optimal route for data transmission.
Which type of physical media uses light pulses for data transmission?
A. Twisted Pair Cable
B. Coaxial Cable
C. Fiber Optic Cable
D. Radio Waves
What is the main advantage of digital signals over analog signals?
A. Digital signals can take on any value within a range.
B. Digital signals are less affected by interference and can be corrected for noise.
C. Digital signals reproduce real-world data more accurately.
Which of the following is an example of unguided media?
Ethernet Cable
Fiber Optic Cable
Radio Waves
Twisted Pair Cable
What is attenuation in the context of the physical layer?
The delay caused by signal transmission.
The maximum data capacity of a medium.
The weakening of a signal as it travels over a distance.
The unwanted signals that interfere with data transmission.
What is the role of a repeater in a network?
To broadcast signals to all connected devices in a LAN.
To amplify or strengthen signals over long distances.
To convert analog signals into digital format for transmission.
To manage the flow of data between different network layers.
In a DNS spoofing (cache poisoning) attack, what is the primary vulnerability being exploited?
Weak encryption between DNS servers.
The reliance on cached DNS records for faster lookups.
The inability of DNS servers to respond to multiple requests simultaneously.
The use of outdated software on DNS resolvers.
What is the difference between a DoS and a DDoS attack?
DoS attacks target applications, while DDoS attacks target networks.
DoS attacks use a single machine, whereas DDoS attacks use multiple machines, often part of a botnet.
DoS attacks overwhelm servers with malformed packets, whereas DDoS attacks only use ICMP floods.
DoS attacks are more powerful than DDoS attacks due to higher bandwidth usage.
In an eavesdropping attack, what can an attacker NOT do?
Intercept network traffic.
Analyze intercepted data for sensitive information.
Modify intercepted data before it reaches its destination.
Listen to unencrypted traffic on a network segment.
How does a man-in-the-middle (MITM) attack differ from eavesdropping?
MITM allows the attacker to modify traffic, while eavesdropping only permits listening.
MITM requires physical access to the network, whereas eavesdropping does not.
Eavesdropping can be used for DNS spoofing, while MITM cannot.
MITM attacks target wireless networks, while eavesdropping targets wired networks.
What is the best defense against DNS hijacking attacks?
Use encryption for all DNS queries.
Validate DNS responses against trusted resolvers.
Limit DNS cache sizes to reduce stored records.
Use random ports for DNS queries to confuse attackers.
What does the physical topology of a network define?
The logical flow of data between devices.
The physical arrangement of devices and connections in the network.
The IP addressing scheme used in the network.
The protocols operating on the transport layer.
Which of the following best describes the role of modulation in the physical layer?
It detects errors in transmitted signals.
It encodes data into a signal suitable for transmission over the physical medium.
It encrypts data for secure transmission.
It establishes logical connections between transmitting devices.
Which type of signal is generally more resistant to noise and can be corrected for errors over long distances?
Analog signals
Digital signals
Radio signals
Optical signals
What is the primary goal of a Denial of Service (DoS) attack?
To gain unauthorized access to sensitive data.
To encrypt a victim’s data for ransom.
To disrupt the availability of a network or service.
To eavesdrop on communication between two parties.
How does DNS hijacking affect users?
It redirects users to malicious websites without their knowledge.
It encrypts DNS queries to prevent tracking.
It floods DNS servers with requests to make them unavailable.
It slows down the resolution process by adding additional hops.
What is one of the main challenges unique to wireless networks compared to wired networks?
Maintaining high-speed data rates across all devices.
Managing communication over a wireless link.
Guaranteeing no data loss during transmission.
Maintaining a permanent physical connection.
In a wireless network, what is the role of a base station?
To act as a central node for all wireless hosts.
To establish direct connections between mobile devices.
To relay packets between the wired network and wireless hosts in its area.
To encrypt and secure all data transmissions in its range.
Which of the following is a feature of ad hoc wireless networks?
Requires a fixed infrastructure, such as access points or base stations.
Relies on nodes organizing themselves and routing data among each other.
Offers better performance than infrastructure-based networks.
Always provides access to the larger Internet.
Which type of wireless network does not involve any infrastructure?
Cellular network
Wi-Fi network with access points
Ad hoc network
Satellite communication
In which scenario would a multiple-hop wireless network typically be used?
When connecting directly to a base station.
In environments with stable high-speed wired backbones.
In mesh networks where hosts relay data to reach a larger Internet.
In environments that require a single-hop link for speed.
What does VANET stand for in wireless networking?
Virtual Area Network for Efficient Transmission
Vehicular Ad Hoc Network
Variable Access Network for Enhanced Technology
Versatile Automated Network for Electronic Transfer
What protocol is commonly used to coordinate access to a wireless link?
TCP
Multiple Access Protocol
DHCP
ARP
What is a key feature of mobile networks?
Mobile users can maintain communication as they change their point of attachment to the network.
Mobile networks require physical wires for transmission.
Mobility ensures a permanent IP address for devices.
Wireless networks always include mobility features.
Which wireless network type might use mesh networking?
Single-hop infrastructure network
Cellular network
MANET (Mobile Ad Hoc Network)
Bluetooth network
Why do wireless Internet-connected devices face challenges compared to wired ones?
They require expensive equipment for basic connectivity.
They must deal with mobility and wireless communication issues.
Wireless devices always consume more power than wired devices.
Wireless communication does not support encryption.
What is one of the main challenges unique to wireless networks compared to wired networks?
Maintaining high-speed data rates across all devices.
Managing communication over a wireless link.
Guaranteeing no data loss during transmission.
Maintaining a permanent physical connection.
Which of the following is a feature of ad hoc wireless networks?
Requires a fixed infrastructure, such as access points or base stations.
Does not require a fixed infrastructure, such as access points or base stations.
Which type of wireless network does not involve any infrastructure?
Cellular network
Wi-Fi network with access points
Ad hoc network
Satellite communication
In which scenario would a multiple-hop wireless network typically be used?
When connecting directly to a base station.
In environments with stable high-speed wired backbones.
In networks where hosts relay data to reach a larger Internet.
In environments that require a single-hop link for speed.
What does VANET stand for in wireless networking?
Virtual Area Network Ethernet Technology
Vehicular Ad Hoc Network
Visual Access Network Enabled Technology
Virtual Ad Hoc Node Emulation Technique
What protocol is commonly used to coordinate access to a wireless link?
TCP
Multiple Access Protocol
DHCP
ARP
What is a key feature of mobile networks?
Mobile users can maintain communication as they change their point of attachment to the network.
Mobile networks require physical wires for transmission.
Mobility ensures a permanent IP address for devices.
Wireless networks always include mobility features.
Why do wireless Internet-connected devices face challenges compared to wired ones?
They require expensive equipment for basic connectivity.
They must deal with mobility and wireless communication issues.
Wireless devices always consume more power than wired devices.
What is the primary characteristic of Code Division Multiple Access (CDMA)?
A. It assigns unique frequencies to each user.
B. It assigns unique codes to each user for simultaneous transmission.
C. It divides time into slots and assigns them to users.
D. It requires users to transmit at different power levels.
