Computer Networks Important Questions

Unit I

Network Models & Physical Layer

Hardware, Software, OSI, TCP/IP, Transmission Media & Data Link Basics

1-Mark Questions

15

What is computer network hardware?
What is the role of network software?
List the layers of the OSI reference model.
List the layers of the TCP/IP reference model.
What was the significance of ARPANET?
What is guided transmission media? Give examples.
What are the characteristics of twisted pair cables?
What is the advantage of fiber optic cables over copper cables?
What is wireless transmission?
What is the primary function of the data link layer?
What is framing in the data link layer?
What is the difference between error detection and error correction?
What is parity checking?
What is the purpose of the physical layer?
Define network topology.

5-Mark Questions

12

Explain the components of network hardware with examples.
Explain network software and protocol hierarchies.
Compare the OSI reference model and the TCP/IP reference model.
Explain the historical significance and architecture of ARPANET.
Explain guided transmission media: twisted pairs, coaxial cable, and fiber optics.
Explain wireless transmission media and its applications.
Explain the design issues of the data link layer.
Explain framing methods used in the data link layer.
Explain error detection techniques using checksum or CRC.
Explain Hamming code for error correction.
Explain how fiber optic cables transmit data using total internal reflection.
Explain the role of physical layer interfaces and standards.

10-Mark Questions

6

Explain the OSI reference model in detail, describing the functions and responsibilities of each of the seven layers.
Explain the TCP/IP reference model and compare its layer structure with the OSI reference model.
Explain guided and unguided transmission media in detail, discussing their types, advantages, and limitations.
Explain data link layer design issues, framing techniques, and error detection/correction methods with suitable examples.
Explain the evolution and architecture of ARPANET and its impact on the modern Internet.
Develop a comprehensive overview of physical layer communication principles, transmission media, and switching basics.

Unit II

Data Link Control & Medium Access Sublayer

Elementary Protocols, Sliding Window, MAC Protocols, Wireless LANs & Switching

1-Mark Questions

15

What is an elementary data link protocol?
What is a simplex protocol?
What is a stop-and-wait protocol?
What is a sliding window protocol?
What is the main difference between Go-Back-N and Selective Repeat?
What is the channel allocation problem in broadcast networks?
What is ALOHA and what are its types?
What is CSMA (Carrier Sense Multiple Access)?
What is collision avoidance in wireless networks?
What are collision-free protocols?
What is a Wireless LAN (WLAN)?
What is data link layer switching?
What is the function of a network bridge/switch?
What is piggybacking in data link protocols?
What is the window size in a 1-bit sliding window protocol?

5-Mark Questions

12

Explain the simplex stop-and-wait protocol for an error-free channel.
Explain the simplex stop-and-wait protocol for a noisy channel (Stop-and-Wait ARQ).
Explain the operation of a 1-bit sliding window protocol.
Explain the Go-Back-N sliding window protocol with a timeline diagram.
Explain the Selective Repeat sliding window protocol and its advantages over Go-Back-N.
Explain the channel allocation problem in static versus dynamic allocation.
Explain Pure ALOHA and Slotted ALOHA with their throughput formulas.
Explain Carrier Sense Multiple Access (CSMA) protocols and persistence strategies.
Explain collision-free protocols such as bit-map and token ring protocols.
Explain the architecture and working principles of Wireless LANs (IEEE 802.11).
Explain data link layer switching and transparent bridges.
Explain how virtual LANs (VLANs) operate at the data link layer.

10-Mark Questions

6

Explain sliding window protocols in detail, covering 1-bit sliding window, Go-Back-N, and Selective Repeat protocols.
Explain multiple access protocols in detail, discussing ALOHA, CSMA variants, and collision-free protocols.
Explain Wireless LAN architectures, medium access control mechanisms, and security features in IEEE 802.11 networks.
Explain data link layer switching, bridge operations, spanning tree algorithms, and layer-2 switch forwarding.
Explain the channel allocation problem in broadcast networks and compare static channel allocation with dynamic allocation methods.
Develop an analytical comparison of sliding window error control protocols with real-world networking examples.

Unit III

Network Layer

Design Issues, Routing Algorithms, Congestion Control, QoS & Internetworking

1-Mark Questions

15

What is the primary function of the network layer?
What is the difference between virtual circuit and datagram networks?
What is routing?
What is shortest path routing?
What is flooding in routing?
What is hierarchical routing?
What is broadcasting and multicasting?
What is distance vector routing?
What is the count-to-infinity problem?
What is network congestion?
What is Quality of Service (QoS)?
What is internetworking?
What is the role of the network layer in the Internet (IP protocol)?
What is an IP address?
What is subnetting?

5-Mark Questions

12

Explain network layer design issues, including store-and-forward packet switching and services provided to the transport layer.
Compare virtual circuit and datagram subnets.
Explain Dijkstra's shortest path routing algorithm with an example.
Explain flooding and its variants (selective flooding) in computer networks.
Explain hierarchical routing and why it is essential for large networks.
Explain broadcast and multicast routing algorithms.
Explain distance vector routing and how routing tables are updated using the Bellman-Ford equation.
Explain congestion control algorithms (open-loop and closed-loop controls).
Explain Quality of Service (QoS) requirements and techniques like traffic shaping and token bucket.
Explain internetworking and how heterogeneous networks are connected using routers and gateways.
Explain the structure and operation of the network layer in the Internet (IPv4 header and addressing).
Explain link-state routing and routing information protocol (RIP).

10-Mark Questions

6

Explain routing algorithms in detail, comparing shortest path routing, distance vector routing, and link-state routing.
Explain congestion control algorithms and Quality of Service (QoS) mechanisms used in packet-switched networks.
Explain internetworking principles, packet fragmentation, tunneling, and the operation of the network layer in the Internet (IPv4/IPv6).
Explain hierarchical routing, broadcast routing, and multicast routing architectures for large-scale networks.
Explain the design issues of the network layer, contrasting connection-oriented (virtual circuit) and connectionless (datagram) services.
Develop a detailed analysis of routing table updates, loop prevention mechanisms, and congestion management.

Unit IV

Transport Layer

Services, Protocol Elements, Connection Management, TCP & UDP

1-Mark Questions

15

What is the main role of the transport layer?
What are transport services (connection-oriented vs connectionless)?
What is multiplexing and demultiplexing in the transport layer?
What is flow control at the transport layer?
What is crash recovery in transport protocols?
What is connection establishment and release?
What is a three-way handshake in TCP?
What is TCP (Transmission Control Protocol)?
What is UDP (User Datagram Protocol)?
What is a socket address?
What is the difference between TCP and UDP?
What is congestion control in TCP?
What is a sequence number in TCP segments?
What is an acknowledgment number?
What is the port number concept?

5-Mark Questions

12

Explain transport services and the relationship between the transport layer and network layer.
Explain the elements of transport protocols such as addressing, connection establishment, and release.
Explain connection management in transport protocols using the three-way handshake.
Explain error control and flow control mechanisms in transport protocols.
Explain multiplexing, demultiplexing, and crash recovery in transport layers.
Explain the architecture and header format of the User Datagram Protocol (UDP).
Explain the architecture and header format of the Transmission Control Protocol (TCP).
Explain TCP connection release mechanisms (graceful release vs abrupt release).
Explain TCP sliding window flow control and window management.
Explain TCP congestion control mechanisms (slow start, congestion avoidance, fast recovery).
Compare TCP and UDP across various parameters and application use cases.
Explain timer management in transport protocols.

10-Mark Questions

6

Explain the Transmission Control Protocol (TCP) in detail, covering its segment structure, connection management, flow control, and reliability features.
Explain TCP congestion control algorithms and how TCP handles network congestion dynamically.
Explain the User Datagram Protocol (UDP), comparing its design philosophy, header layout, and use cases with TCP.
Explain transport layer protocol elements, including addressing, connection setup/teardown, multiplexing, and crash recovery.
Explain reliable data transfer mechanisms and timer management strategies implemented at the transport layer.
Develop a comparative study of transport layer protocols and their suitability for real-time versus reliable data streaming applications.

Unit V

Application Layer

DNS, SNMP, Electronic Mail, World Wide Web, HTTP & Streaming Media

1-Mark Questions

15

What is the application layer in computer networks?
What is the Domain Name System (DNS)?
What is SNMP (Simple Network Management Protocol)?
What is electronic mail (Email) architecture?
What is the World Wide Web (WWW)?
What is HTTP (Hypertext Transfer Protocol)?
What is streaming audio and video?
What is a DNS resolver and root server?
What is MIME in electronic mail?
What is the difference between persistent and non-persistent HTTP?
What is a Uniform Resource Locator (URL)?
What is FTP (File Transfer Protocol)?
What is SMTP, POP3, and IMAP?
What is adaptive streaming for multimedia?
What is a cookie in web applications?

5-Mark Questions

12

Explain the Domain Name System (DNS) and its hierarchical name resolution process.
Explain Simple Network Management Protocol (SNMP) architecture and management information base (MIB).
Explain electronic mail architecture, user agents, message transfer agents, and mail access protocols.
Explain the World Wide Web architecture and how browsers interact with web servers.
Explain HTTP request-response messages, methods, and status codes.
Explain persistent versus non-persistent HTTP connections.
Explain streaming audio and video technologies, codecs, and content delivery networks (CDNs).
Explain email protocols: SMTP, POP3, and IMAP.
Explain DNS record types (A, CNAME, MX, NS) and zone transfers.
Explain web caching and proxy servers in improving web performance.
Explain real-time streaming protocols (RTSP, RTP) for multimedia applications.
Explain security aspects in application layer protocols (HTTPS, DNSSEC).

10-Mark Questions

6

Explain the Domain Name System (DNS) in detail, including domain namespace, name servers, recursive/iterative queries, and record caching.
Explain Electronic Mail architecture and protocols, covering SMTP, POP3, IMAP, and MIME message formats.
Explain the World Wide Web and HTTP protocol in detail, including persistent/non-persistent connections, cookies, caching, and HTTP/HTTPS headers.
Explain streaming audio and video technologies, discussing multimedia compression, streaming protocols, buffering, and CDN infrastructures.
Explain Simple Network Management Protocol (SNMP), network management framework, agents, managers, and management information bases.
Develop an exhaustive review of modern application layer protocols and their supporting role in internet services.