Introduction
Computer networking is the backbone of modern communication. To make devices talk to each other, engineers use reference models like OSI (Open Systems Interconnection) and TCP/IP (Transmission Control Protocol/Internet Protocol). Both models explain how data moves from one device to another, but they differ in structure, layers, and approach.
This guide covers:
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✅ What is the OSI Model?
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✅ What is the TCP/IP Model?
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✅ Functions of each layer
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✅ Key differences between OSI and TCP/IP
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✅ FAQs for students & interview prep
🌐 OSI Model (Open Systems Interconnection)
The OSI Model was developed by ISO in 1984. It has 7 layers, each with a specific function.
OSI Layers and Functions:
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Physical Layer – Deals with hardware, signals, cables.
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Data Link Layer – Ensures error-free data transfer between two nodes.
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Network Layer – Handles routing and addressing (IP addresses).
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Transport Layer – Provides reliable delivery (TCP/UDP).
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Session Layer – Manages connections and sessions between devices.
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Presentation Layer – Data translation, encryption, compression.
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Application Layer – User interface, network services (HTTP, FTP, SMTP).
👉 Think of OSI as a step-by-step process, from raw signals to user applications.
🌍 TCP/IP Model (Transmission Control Protocol / Internet Protocol)
The TCP/IP Model is the foundation of the internet. It is practical and widely used in real-world networking. Unlike OSI’s 7 layers, TCP/IP has 4 layers.
TCP/IP Layers and Functions:
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Network Access Layer – Similar to OSI’s Physical + Data Link.
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Internet Layer – Responsible for addressing and routing (IP protocol).
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Transport Layer – Ensures error-free communication (TCP, UDP).
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Application Layer – Combines OSI’s session, presentation, and application layers.
👉 TCP/IP is considered more practical as it directly maps to internet protocols.
📌 Why Computer Networks MCQs Are Important?
Computer Networks is one of the most important subjects in IT and computer science. Most exams include questions from:
TCP/IP model and its layers
OSI reference model (7 layers)
Protocols like SMTP, FTP, DNS, HTTP, POP, IMAP, ARP, SNMP
Error detection and correction techniques
Client-Server and Peer-to-Peer models
IP addressing and routing algorithms
Practicing these MCQs will help you improve speed, accuracy, and confidence in exams.
Computer Networks MCQs with Answers (TCP/IP & OSI Model)
TCP/IP and OSI Model MCQs
Q1. Your business has contracted with another company to host and run an application over the Internet. The company providing this service is called?
(A) Internet Service Provider (ISP)
(B) Internet Access Provider (IAP)
(C) Application Service Provider (ASP) ✅
(D) Application Access Provider
Q2. ARP (Address Resolution Protocol) is:
(A) A TCP/IP protocol used to bind IP to hardware ✅
(B) A high-level protocol for file transfer
(C) A protocol for monitoring computers
(D) A protocol for error messages
Q3. An SMTP session may include:
(A) Zero SMTP transaction
(B) One SMTP transaction
(C) More than one SMTP transaction
(D) All of the above ✅
Q4. Which protocol is used to receive mail messages?
(A) SMTP
(B) POP ✅
(C) IMAP ✅
(D) All of the above ✅
Q5. SMTP connections secured by SSL are known as:
(A) SMTPS ✅
(B) SSMTP
(C) SNMP
(D) All of these
Q6. Which protocol is used for transferring files?
(A) RARP
(B) ARP
(C) TCP
(D) FTP ✅
Q7. FTP stands for:
(A) File Translate Protocol
(B) File Transfer Protocol ✅
(C) File Typing Protocol
(D) File Tensile Protocol
Q8. POP denotes:
(A) Post Office Protocol ✅
(B) Protocol on Protocol
(C) Popular Office Program
(D) Post Office Program
Q9. Downloading a document means:
(A) File transferred from another computer to yours ✅
(B) Uploading
(C) Accessing
(D) Syndication
Q10. A company website is hosted on a:
(A) Web client
(B) Web server ✅
(C) Web page
(D) Web infrastructure
🖧 OSI Model MCQs
Q11. Which is not a function of a server?
(A) E-mail processing
(B) Database sharing
(C) Word processing ✅
(D) Processing websites
Q12. Which of the following is not a layer of the OSI model?
(A) Internet Layer ✅
(B) Application Layer
(C) Transport Layer
(D) Presentation Layer
Q13. Railway reservation system is an example of:
(A) Client-Server Network ✅
(B) 3-Tier Network ✅
(C) Peer-to-Peer Network
(D) Both A and B ✅
Q14. Internet is an example of:
(A) Client-Server Network ✅
(B) 3-Tier Network
(C) Peer-to-Peer Network
(D) Both A and B
Q15. OSI Model includes how many layers?
(A) 5
(B) 4
(C) 7 ✅
(D) 6
Q16. OSI Model was first described by:
(A) Henry F. Korth
(B) Vinton Cerf
(C) Hubert Zimmermann ✅
(D) Charles Babbage
Q17. OSI Model was certified by ISO in the year:
(A) 1983
(B) 1978
(C) 1980
(D) 1984 ✅
Q18. In OSI, each layer provides services to its:
(A) Upper Layer ✅
(B) Lower Layer
(C) Both
(D) None
Q19. In OSI, data compression is carried out by:
(A) Network Layer
(B) Presentation Layer ✅
(C) Physical Layer
(D) Data Link Layer
Q20. Data Link Layer is responsible for:
(A) Framing ✅
(B) Flow Control ✅
(C) Error Control ✅
(D) All of these ✅
📡 TCP/IP Model MCQs
Q21. TCP/IP Model is a:
(A) 7 Layer Model
(B) 5 Layer Model
(C) 4 Layer Model ✅
(D) 6 Layer Model
Q22. TCP/IP was developed by:
(A) Vint Cerf & Bob Kahn ✅
(B) Bill Gates
(C) Hubert Zimmerman
(D) Tim Berners-Lee
Q23. TCP/IP is a:
(A) Single Protocol
(B) Suite of Protocols ✅
(C) Application Package
(D) Medium
Q24. Which of the following protocol is connection-less?
(A) UDP ✅
(B) TCP
(C) FTP
(D) HTTP
Q25. Which protocol converts IP to MAC address?
(A) IP
(B) ARP ✅
(C) RARP
(D) SMTP
📂 Error Detection & Network Devices MCQs
Q26. Error detection at the data link layer is achieved by:
(A) CRC ✅
(B) Hamming Codes
(C) Bit Stuffing
(D) Equalization
Q27. Parity Bit is used for:
(A) Error detection ✅
(B) Byte recognition
(C) Token management
(D) Addressing
Q28. Which device works at OSI Physical Layer?
(A) Repeater ✅
(B) Router
(C) Switch
(D) Bridge
Q29. Which layer is responsible for routing?
(A) Session
(B) Data Link
(C) Network ✅
(D) Physical
Q30. DNS is used to locate:
(A) MAC address of URL
(B) IP address of URL ✅
(C) Root domain
(D) Protocol type
📝 Conclusion
Computer Networks is a scoring subject if you practice well. By solving these MCQs with answers, you can strengthen your concepts and boost your exam performance. Focus on:
OSI Model (7 layers)
TCP/IP Model (4 layers)
Application Layer Protocols (HTTP, FTP, SMTP, DNS)
Routing Algorithms (RIP, OSPF, BGP)
Error Detection Methods (CRC, Parity)
❓ Frequently Asked Questions – TCP/IP & OSI Model MCQs
Q1. How many layers are there in the OSI Model?
👉 The OSI Model has 7 layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application.
Q2. How many layers are there in the TCP/IP Model?
👉 The TCP/IP Model has 4 layers: Application, Transport, Internet, and Network Access (Link).
Q3. Which protocol is used to transfer files between two systems?
👉 FTP (File Transfer Protocol) is used for file transfer.
Q4. Which protocol is used to convert IP address to MAC address?
👉 ARP (Address Resolution Protocol) converts an IP address into a MAC address.
Q5. What is the difference between TCP and UDP?
👉 TCP is connection-oriented (reliable, uses handshake) while UDP is connection-less (faster but less reliable).