This document contains 30 important questions related to data communication networks for a pre-university exam. The questions cover a range of topics including comparing TCP and OSI models, explaining IPv6, drawing and explaining the TCP/IP architecture, different network devices, transmission mediums, ALOHA protocols, congestion control algorithms, routing algorithms like Dijkstra's, data rates and bandwidth, error detection methods, network switching, application and transport layers, Hamming codes, technologies like Bluetooth, cryptography, ATM, network security, generations of Ethernet, PPP and HDLC frame structures, differences between various guided and unguided media, protocols, topologies, and cables, CSMA/CD networks, and ARQ protocols.

1. ASHOKA INSTITUTE OF TECHNOLOGY & MANAGEMENT, AKTHA, SARNATH,
VARANASI, UTTAR PRADESH
MOCK PAPER
30 IMPORTANT QUESTIONS (PRE UNIVERSITY EXAM/GBTU END SEMESTER EXAM-2013)
FACULTY NAME: - ER. ANUPAM KUMAR, ECE, ASSISTANT PROFESSOR, AITM
SUBJECT CODE & TITLE: -EEC702 & DATA COMMUNICATION NETWORKS
1. Compare TCP and OSI model.
2. Explain the IPv6 newer protocol. What are its advantages over IPv4? Discuss.
3. Draw the TCP/IP network architectural model and explain the features of various layers.
Also list the important protocols at each layer and describes its purposes. Briefly describe
the difference between the OSI and TCP/IP architectural model.
4. What is the basic of network connecting devices? With the help of suitable explanatory
diagram, explain various network connecting devices.
5. Explain in brief different types of mediums for communication.
6. What are the differences between Pure ALOHA and Slotted ALOHA?
7. What do you understand by non-persistent CSMA?
8. What is congestion control? How it is control using token buckets as well as leaky bucket
algorithm.
9. Explain in details the Dijsktra’s Algorithm for shortest path with the help of suitable
diagram.
10. Explain the relationship between Data Rate and Bandwidth.
11. What is the use of Bit stuffing in data?
12. Explain the reservation protocols? Where do we use these?
13. Explain in detail Flooding. What do you understand by selective flooding? Also explain
Flow based Routing.
14. Why do we use layered protocols? Give atleast two reasons.
15. Explain with the help of diagrams the TCP Segment Header. And also explain TCP
Connection management.
16. What are the different elements of transport protocols? Also explain how do we establish
a connection?

2. 17. Given the dataword 1010011110 and the divisor 10111, a. Show the generation of the
codeword at the sender site (using binary division). b. Show the checking of the
codeword at the receiver site (assume no error).Using polynomials.
18. Define piggybacking and its usefulness.
19. What do you mean by multiple access & Random access communications?
20. Explain Carrier Sense Multiple Access (CSMA) and CSMA/CD. And also draw the neat
& clean flow-chart for this method.
21. Explain Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA). And also
draw the neat & clean flow-chart for this method.
22. What are the different types of error detection methods? Generate .the CRC (Cyclic
Redundancy Check) code for message 1101010101.Given generator polynomial g(x)
=X4+X2+1.
23. Explain Datagram Network switching with the help of suitable diagram.
24. Explain with the help of suitable diagram, the Application layer in OSI Model and
transport layer in the TCP/IP Suite.
25. If the 7- bit Hamming codeword received by a receiver is 1011011.Assuming the even
parity; State whether the received codeword is correct or wrong. If wrong, locate the bit
in error.
26. Write a short note on:
 Bluetooth
 Cryptography
 ATM
 Network Security
 TCP/IP
 Generations of Ethernet
27. Explain the PPP with its frame structure. Or, Explain the HDLC with its frame structure.
28. Explain difference between:
 Guided vs. Unguided Media
 UDP vs. TCP
 Multicast and Broadcast
 STP and STP
 IPv4 and IPv6
 Thick and Thin Ethernet
 LAN AND WAN
 Mesh and Star Topology
 Wired and Wireless Media
 Twisted-Pair, Co-axial cable and Fiber-optic Cable
29. What is CSMA/CD? Consider building a CSMA/CD network running at 1Gbps over a
1Km cable with no repeaters. The signal speed in the cable is 20,0000Km/s. What is the
minimum frame size?
30. Explain working of Go-back-N ARQ sliding window protocol. OR, explain the concept
of stop-and-wait ARQ protocol with a suitable example.