CY-403 Computer Networks - Nov 2023 Question Paper

Under each question, How to answer lists the points an answer should cover, outlined by CampusPrep from the syllabus. Check the details against your textbook.

1. 7 Marks
   aDifference between server based and Peer to Peer Networking.
   How to answer

   • Define server-based networking with centralized server roles
   • Define peer-to-peer networking with equal peers
   • Compare on control, cost, scalability, security, reliability
   • Give examples of each
2. 7 Marks
   bExplain the term Nyquist bit rate and Shannon capacity.
   How to answer

   • State Nyquist bit rate formula $R = 2B \log_2 L$
   • Explain bandwidth and signal levels
   • State Shannon capacity $C = B \log_2(1+SNR)$
   • Explain noisy channel implication with example
3. 7 Marks
   aExplain MAC along with working of all CSMA protocols.
   How to answer

   • Define MAC and its role in data link layer
   • Explain CSMA persistence strategies
   • Explain CSMA/CD working steps
   • Explain CSMA/CA working steps
4. 7 Marks
   bWhat is the purpose of Hamming code? Construct Hamming code for the bit sequence $10011101$.
   How to answer

   • State purpose: single-bit error detection and correction
   • Determine number of parity bits for 8 data bits
   • Place parity bits at positions 1,2,4,8 and compute even/odd parity
   • Write final 12-bit Hamming code for 10011101
5. 7 Marks
   aExplain the working of IEEE 802.4 standard. Also explain the working of Frame format.
   How to answer

   • Describe IEEE 802.4 token bus concept and medium
   • Explain token passing and logical ring working
   • Describe frame format fields: preamble, frame control, addresses, data, FCS
   • Explain function of each field
6. 7 Marks
   bImagine the length of ring in token ring is $1000$ meter if the speed of propagation in a twisted pair cables is $60$ percent of the speed of light ($300,000,000$ meter/second). How long does it takes for a bit to make a complete trip?
   How to answer

   • Compute propagation speed $v = 0.6 \times c$
   • Use time = distance / speed for 1000 m ring
   • Calculate $t \approx 5.55 \mu s$
   • State result with units
7. 7 Marks
   aExplain any two unicast static and dynamic routing Algorithms.
   How to answer

   • Define unicast routing and static vs dynamic
   • Explain one static algorithm e.g. shortest path / Dijkstra
   • Explain one dynamic algorithm e.g. distance vector / link state
   • Compare with advantages and applications
8. 7 Marks
   bDescribe subnet mask. Explain different classes of IP address.
   How to answer

   • Define subnet mask and its purpose
   • Explain IP address classes A, B, C, D, E with ranges
   • Explain default masks and network/host division
   • Give examples of subnetting
9. 7 Marks
   aExplain the various congestion control Algorithms.
   How to answer

   • Define congestion and its causes
   • Explain leaky bucket and token bucket algorithms
   • Explain choke packets / RED / slow start
   • Compare open-loop vs closed-loop control
10. 7 Marks
    bExplain the addressing using DNS.
    How to answer

    • Define DNS and its need for name resolution
    • Explain hierarchical name space and zones
    • Explain iterative vs recursive resolution steps
    • Give example of address mapping
11. 7 Marks
    aExplain OSI model stating its importance in network architecture.
    How to answer

    • List seven layers of OSI model
    • Explain function of each layer briefly
    • State importance: standardization, interoperability, modular design
    • Compare with TCP/IP relevance
12. 7 Marks
    bWhat is the principle difference between connectionless and connection oriented communication.
    How to answer

    • Define connection-oriented service with setup phase
    • Define connectionless service with datagrams
    • Compare on reliability, ordering, overhead, applications
    • Give TCP vs UDP examples
13. 7 Marks
    aDiscuss internet services standards for TCP/IP and the process of standardization for RFCS and TCP/IP.
    How to answer

    • List TCP/IP internet services and protocols
    • Explain RFC process and standardization stages
    • Explain TCP/IP standardization procedure
    • State importance of standards
14. 7 Marks
    bExplain distance vector routing with example.
    How to answer

    • Define distance vector concept and Bellman-Ford basis
    • Explain exchange of vectors and routing table update
    • Illustrate with small network example
    • Mention count-to-infinity and split horizon
15. 14 Marks
    Describe Frame Relay Protocol architecture and explain the function of each one.
    How to answer

    • Define Frame Relay and its architecture planes
    • Describe frame format and DLCI, congestion bits
    • Explain functions: multiplexing, error detection, congestion control
    • State applications and advantages