Data Communication Past Papers Exam Questions

By Prof. Fazal Rehman Shamil

Guess Paper 1: Data Communication Fall – 2020 Past Papers

Time Allowed: 3 hours

Total Marks:    70, Passing Marks (35)

Q1. Define the following terms:

a) Physical path and channel
b) Network topology
c) Protocol suit
d) Composite signal
e) Transmission mode

Q2. Give brief introduction of layer architecture and discuss first 3 layers of OSI model in detail.

Q3. What is the importance of multiplexing in data communication? Discuss its different application in detail.

Q4. Give a brief introduction to local area network. Differentiate between FDDI and Token ring network in
detail with suitable examples.

Q5. Explain the concept of switching in data communication along its different categories.

Q6. Write a detail discussion on “Encoding and Modulation” mechanism.

Q7. Write short notes on any two of the following.
a. Error detection and correction
b. Transmission media
c. Data link protocols

Guess Paper 2: Data Communication Spring – 2020 Past Papers

Time Allowed: 3 hours

Total Marks:    70, Passing Marks (35)

Q.1 Multiple Choice Questions
i)____________ Layer responsible for movements of individual bits from one hop (node) to the next.
(a) Physical Layer (b) Data link layer (c) Transport layer
ii) Communication between a computer and a keyboard involves ______________ transmission.
(a)Simplex (b) Half Duplex (c)Full Duplex
iii) Line coding is the process of converting digital data to a ____________ signal.
(a) Digital (b) Analog (c) Hybrid
iv) Frequency-division multiplexing (FDM) is a _____________ technique
(a) Digital (b) Analog (c) Hybrid
v) The process-to-process delivery of the entire message is the responsibility of the _______ layer.
(a) Transport (b) Application (c) Physical
vi) A digital signal is a composite analog signal with a/an __________ bandwidth.
(a)Infinite (b) Finite (c)Unlimited
vii)The physical, data link, and ____________ layers are the network support layers.
(a) Network (b) Transport (c) Presentation

Q2. (a) What are the differences between parallel and serial transmission?
(b) Differentiate between TCP/IP Protocol suits and OSI Model?

Q3 (a) A complex low-pass signal has a bandwidth of 200 kHz. What is the minimum sampling rate for this signal?
b) We want to digitize the human voice. What is the bit rate, assuming 8 bits per sample? (Hint: The human voice normally contains frequencies from 0 to 4000 Hz)

Q4 (a)What are the two approaches to packet-switching?
(b) Distinguish between a link and a channel in multiplexing?

Q5 (a) List three techniques of digital-to-digital conversion?
(b) What are the advantages of dividing an Ethernet LAN with a bridge?

Q6 (a) An analog signal carries 4 bits per signal element. If 1000 signal elements are sent per second,
find the bit rate?
(b) Define each term PSK, FSK and ASK.

Q7 (a) How does a single-bit error differ from a burst error?
(b) How do guided media differ from unguided media?

Q.8 Write short notes on any two of the following:
a). Checksum b). Attenuation c). Time Division Multiplexing (TDM)

Guess Paper 3: Data Communication Spring – 2019 Past Papers

Time Allowed: 3 hours

Total Marks:    70, Passing Marks (35)

Q1. Define the following terms:

i. Full Duplex
ii. Serial and parallel transmissions
iii. Periodic signal
iv. Burst error
v. Composite signal

Q2. Write a comprehensive note on OSI reference model.

Q3. Explain the importance and functionality of guided media in detail.

Q4. Discuss the in detail the encoding and modulation techniques.

Q5. Discuss the need of error detection and correction method. Also explain the working of VRC with a
comprehensive example.

Q6. Write a detailed note on local area networks.

Q7. Write short notes on the following.
i. Analog and Digital signals
ii. Multiplexing

Guess Paper 4: Data Communication Fall – 2019 Past Papers

Time Allowed: 3 hours

Total Marks:    70, Passing Marks (35)

Q1. Define the following terms:

i. Full Duplex
ii. Serial and parallel transmissions
iii. Periodic signal
iv. Burst error
v. Composite signal

Q2. Write a comprehensive note on OSI reference model.

Q3. Explain the importance and functionality of guided media in detail.

Q4. Discuss the in detail the encoding and modulation techniques.

Q5. Discuss the need of error detection and correction method. Also explain the working of VRC with a
comprehensive example.

Q6. Write a detailed note on local area networks.

Q7. Write short notes on the following.
i. Analog and Digital signals
ii. Multiplexing

Guess Paper 5: Data Communication Spring – 2018 Past Papers

Time Allowed: 3 hours

Total Marks:    70, Passing Marks (35)

Q.1 Attempt all parts of this question. (30 marks)

A. Write down True or False for the following (10 marks)
a. Twisted Pair cable is the most widely used transmission media in Local Area Network (LAN).
b. Port number is assigned at application layer which identifies the specific process or service in the end system.
c. In Virtual Circuit (VC) switching data is transmitted over a packet switched network where the paths are identified by the VC numbers.
d. FECN and BECN bits are used in the Frame Relay networks for congestion avoidance.
e. In the Internet Protocol (IP) hostname to IP address mapping is done by the ARP (Address Resolution Protocol).

B. Choose the correct option. (10 marks)
a. On a busy router port the incoming packets are stored in
a) Firewall c) Queue/Buffer of the router
b) Email Server d) Queue/Buffer of the receiver node
b. DLCI (Data link connection identifier) is used in ….. networks to assign frames to PVC or SVC.
a) ATM c) Ethernet networks
b) Frame Relay d) both (a) and (b)
c. Repeaters and Hubs are …. devices.
a) Network Layer c) Data Link Layer
b) Application Layer d) Physical Layer
d. In a “class B” IPv4 address scheme the number of bits reserved for Network ID are
a) 8 bits c) 16 bits
b) 24 bits d) 32 bits
e. ATM Cell size is …. Bytes.
a) 52 c) 65535
b) 128 d) 512

C. Fill in the blanks (10 marks)
a. IPv6 consists total of ……. bits.
b. TFTP stands for …. .
c. ICMP stands for … .
d. UDP is used at …. layer for real time multimedia transmission.
e. IP addresses are assigned at … layer of OSI model.

Q.2 What is Multiplexing? Explain Frequency and Time division multiplexing (FDM and TDM) in detail
with examples/diagrams? (10 marks)

Q.3 Explain Circuit Switching and Packet Switching in detail with example for each specific type? Provide
diagrams for the two types of Packet Switching that is (a) datagram and (b) virtual circuit switching.
(10 marks)

Q.4 What is a Frame Relay? Explain Packet format, DLCI assignment and Congestion avoidance scheme in Frame Relay networks? (10 marks)

Q.5 What is Transmission Media? Write different types of Transmission Media used in Computer Networks. Explain briefly Cable Media. (10 marks)

Q.6 What is Domain Name System (DNS)? Briefly explain flat name space and hierarchical name space with diagrams. Explain the need of DNS in the IP networks? (3+4+3=10 marks)

Q.7 Write short note on any two of the following: (10 marks)
a) ISDN, its services and layers
b) Simple Network Management Protocol (SMNP)
c) ATM and its connection types (PVC and SVc)
d) Flow control schemes of the Data Link Layer

Prof.Fazal Rehman Shamil (Available for Professional Discussions)
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