CSC 311 Introduction to Computer Networks Resit 2025

About this paper

CSC 311: First Semester Resit Examination, University of Buea, Faculty of Science, Department of Computer Science, Course CSC311 Introduction to Computer Networks, Wed 05/03/2025. Section A (20 marks): Question I on optic fibre cables (structure/operation, OSI layer, full-duplex, advantages); Question II on routing concepts (network identification, routing in practice, router's OSI layer, static vs dynamic routing, PDU between routers, OSPF/RIP metrics, default route, router interface addressing, broadcast handling); Question III on IP addressing (smallest/largest address, class D use, best class for small networks, Class B default mask, and a subnetting problem on 12.12.0.0/24 -- valid hosts, broadcast address, public/private classification, and deriving a /27 subnet for 28 hosts). Section B (50 marks): tracing an email's journey across all seven OSI layers with protocols involved (SMTP, DNS, TCP, IP, BGP, Ethernet/Wi-Fi, POP3/IMAP), tracing non-delivery failures layer by layer, the importance and techniques of network resource allocation, three wireless security threats mapped to the Confidentiality/Integrity/Availability triad, and how Camtel could apply dynamic QoS-based resource allocation to relieve network congestion. Source was an annotated exam copy with the instructor's own brief marking-key notes interspersed in the question text (no student PII); only the printed questions were transcribed, with independently derived complete answers.