WGU D413 OBJECTIVE
ASSESSMENT 2 LATEST 2026
ACTUAL EXAM TEST BANK |
D413 TELECOMM AND
WIRELESS COMMUNICATIONS
OA FINAL EXAM
Total Questions: 100+
Part 1: Networking Fundamentals & The OSI Model
1. At which layer of the OSI model do routers primarily operate?
A) Physical
B) Data Link
C) Network
D) Transport
Rationale: Routers forward packets based on logical IP addresses, which is a
function of the Network layer (Layer 3) .
FOR STUDY RESOURCES
,2. Which layer of the OSI model is responsible for end-to-end error recovery and
flow control?
A) Network
B) Transport
C) Session
D) Data Link
Rationale: The Transport layer (e.g., TCP) ensures reliable delivery, error checking,
and sequencing of data between hosts .
3. What is the primary purpose of the Data Link layer?
A) To establish, manage, and terminate sessions.
B) To provide physical transmission of bits over a medium.
C) To ensure reliable, error-free node-to-node delivery of frames.
D) To route packets across different networks.
Rationale: The Data Link layer (Layer 2) handles communication between directly
connected nodes, using MAC addresses and performing error detection on
frames.
4. Which layer of the OSI model is responsible for establishing, managing, and
terminating sessions between applications?
A) Presentation
B) Transport
C) Session
D) Application
Rationale: The Session layer (Layer 5) sets up, coordinates, and terminates
conversations, exchanges, and dialogues between applications .
FOR STUDY RESOURCES
,5. Encryption and data formatting are typically handled at which OSI layer?
A) Application
B) Presentation
C) Session
D) Transport
Rationale: The Presentation layer (Layer 6) acts as a translator, handling data
encryption, compression, and formatting (e.g., JPEG, ASCII) .
6. Which IEEE standard defines Ethernet (the predominant set of LAN
protocols)?
A) 802.11
B) 802.3
C) 802.15
D) 802.1
Rationale: The IEEE 802.3 standard governs Ethernet, including physical layer
cabling and the MAC sublayer .
7. What is the function of a modem?
A) To forward packets based on IP addresses.
B) To connect multiple devices on a LAN.
C) To convert digital signals to analog signals and vice versa.
D) To filter network traffic based on security rules.
Rationale: A modem (modulator-demodulator) converts digital data from a
computer into analog signals for transmission over phone lines (and back again) .
8. What does latency measure in a network?
A) The total amount of data that can be transferred in a second.
FOR STUDY RESOURCES
, B) The delay in data transmission from source to destination.
C) The variation in packet arrival time.
D) The number of packets lost during transmission.
Rationale: Latency is the time it takes for a packet to travel from its source to its
destination .
9. Which type of communication allows data to flow in both directions
simultaneously?
A) Simplex
B) Half-duplex
C) Full-duplex
D) Multiplexed
Rationale: Full-duplex communication allows simultaneous bi-directional data
transmission, like a telephone call .
10. What is the main benefit of a point-to-point link?
A) It provides a direct connection between multiple devices.
B) It provides a dedicated, direct connection between two nodes.
C) It reduces the need for IP addresses.
D) It automatically encrypts all data.
Rationale: A point-to-point link creates a dedicated communication path between
exactly two devices, ensuring a private and direct connection .
11. What is the purpose of a subnet mask?
A) To encrypt data packets.
B) To define which portion of an IP address is the network ID and which is the
host ID.
FOR STUDY RESOURCES
ASSESSMENT 2 LATEST 2026
ACTUAL EXAM TEST BANK |
D413 TELECOMM AND
WIRELESS COMMUNICATIONS
OA FINAL EXAM
Total Questions: 100+
Part 1: Networking Fundamentals & The OSI Model
1. At which layer of the OSI model do routers primarily operate?
A) Physical
B) Data Link
C) Network
D) Transport
Rationale: Routers forward packets based on logical IP addresses, which is a
function of the Network layer (Layer 3) .
FOR STUDY RESOURCES
,2. Which layer of the OSI model is responsible for end-to-end error recovery and
flow control?
A) Network
B) Transport
C) Session
D) Data Link
Rationale: The Transport layer (e.g., TCP) ensures reliable delivery, error checking,
and sequencing of data between hosts .
3. What is the primary purpose of the Data Link layer?
A) To establish, manage, and terminate sessions.
B) To provide physical transmission of bits over a medium.
C) To ensure reliable, error-free node-to-node delivery of frames.
D) To route packets across different networks.
Rationale: The Data Link layer (Layer 2) handles communication between directly
connected nodes, using MAC addresses and performing error detection on
frames.
4. Which layer of the OSI model is responsible for establishing, managing, and
terminating sessions between applications?
A) Presentation
B) Transport
C) Session
D) Application
Rationale: The Session layer (Layer 5) sets up, coordinates, and terminates
conversations, exchanges, and dialogues between applications .
FOR STUDY RESOURCES
,5. Encryption and data formatting are typically handled at which OSI layer?
A) Application
B) Presentation
C) Session
D) Transport
Rationale: The Presentation layer (Layer 6) acts as a translator, handling data
encryption, compression, and formatting (e.g., JPEG, ASCII) .
6. Which IEEE standard defines Ethernet (the predominant set of LAN
protocols)?
A) 802.11
B) 802.3
C) 802.15
D) 802.1
Rationale: The IEEE 802.3 standard governs Ethernet, including physical layer
cabling and the MAC sublayer .
7. What is the function of a modem?
A) To forward packets based on IP addresses.
B) To connect multiple devices on a LAN.
C) To convert digital signals to analog signals and vice versa.
D) To filter network traffic based on security rules.
Rationale: A modem (modulator-demodulator) converts digital data from a
computer into analog signals for transmission over phone lines (and back again) .
8. What does latency measure in a network?
A) The total amount of data that can be transferred in a second.
FOR STUDY RESOURCES
, B) The delay in data transmission from source to destination.
C) The variation in packet arrival time.
D) The number of packets lost during transmission.
Rationale: Latency is the time it takes for a packet to travel from its source to its
destination .
9. Which type of communication allows data to flow in both directions
simultaneously?
A) Simplex
B) Half-duplex
C) Full-duplex
D) Multiplexed
Rationale: Full-duplex communication allows simultaneous bi-directional data
transmission, like a telephone call .
10. What is the main benefit of a point-to-point link?
A) It provides a direct connection between multiple devices.
B) It provides a dedicated, direct connection between two nodes.
C) It reduces the need for IP addresses.
D) It automatically encrypts all data.
Rationale: A point-to-point link creates a dedicated communication path between
exactly two devices, ensuring a private and direct connection .
11. What is the purpose of a subnet mask?
A) To encrypt data packets.
B) To define which portion of an IP address is the network ID and which is the
host ID.
FOR STUDY RESOURCES
