Concept of Layering MCQ Quiz - Objective Question with Answer for Concept of Layering - Download Free PDF

The correct answer is Application Layer, Transport Layer, Internet Layer, Network Interface Layer.

Key Points

• The TCP/IP model is a conceptual framework used to describe the communication processes in networking.
• The layers of the TCP/IP model, arranged from top to bottom, are as follows:
  • Application Layer: This layer is responsible for providing network services to applications. It includes protocols such as HTTP, FTP, SMTP, and DNS.
  • Transport Layer: Ensures reliable communication between devices. Protocols like TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) operate here.
  • Internet Layer: Handles addressing, routing, and packet delivery. The most common protocol in this layer is IP (Internet Protocol).
  • Network Interface Layer: Deals with the physical and data link layers, managing hardware addressing and the actual transmission of data over the network.

Additional Information

• The TCP/IP model is a streamlined version of the OSI model, consisting of only four layers compared to OSI's seven layers.
• It is the foundation of modern internet communication and has been widely adopted globally.
• Each layer in the TCP/IP model has specific tasks and communicates with adjacent layers to ensure seamless data transmission.
• Understanding the TCP/IP model is essential for networking professionals, as it provides a clear structure for troubleshooting and designing networks.

The correct answer is Option 4) Network Interface Layer.

Key Points

• The Network Interface Layer (also known as the Link Layer) is the bottommost layer in the TCP/IP model.
• It is responsible for the physical transmission of data bits over the network using mediums such as Ethernet, WiFi, or Optical Fiber.
• This layer includes both the physical hardware (e.g., cables, network cards) and the data link protocols (e.g., Ethernet, ARP) used to transmit data.
• It handles framing, MAC addressing, and error detection at the link level.

Additional Information

• Option 1 – Transport Layer: Responsible for end-to-end communication and data flow control (e.g., TCP, UDP), not bit-level transmission.
• Option 2 – Application Layer: Deals with user-level protocols like HTTP, FTP, and SMTP.
• Option 3 – Internet Layer: Handles logical addressing, routing, and packet delivery across networks (e.g., IP, ICMP).
• Summary of TCP/IP Layers:
  • Application Layer – User interaction and services
  • Transport Layer – Reliable or unreliable data delivery
  • Internet Layer – Routing and addressing
  • Network Interface Layer – Physical data transmission

The correct answer is: 1) A modem provides internet access, while a NIC manages local area network (LAN) traffic.

Key Differences Between Modem and NIC:

The correct answer is Transport layer.

Key Points

• The Transport layer is responsible for end-to-end communication and error handling between host systems.
  • It ensures that data is transmitted across a network in a reliable manner.
  • Protocols like TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) operate at this layer.
  • The Transport layer segments and reassembles data into a data stream.
  • This layer provides flow control, ensuring that data is sent at a rate that matches the receiver's ability to process it.
  • Error detection and correction mechanisms are implemented at this layer to ensure data integrity.

Additional Information

• The Transport layer is the fourth layer in the OSI (Open Systems Interconnection) model, sitting above the Network layer and below the Session layer.
• It is essential for ensuring that data sent from an application on one host can be correctly received by an application on another host.
• Common applications that rely on the Transport layer include web browsers, email clients, and file transfer programs.
• The Transport layer can also provide multiplexing, allowing multiple applications to use the network simultaneously without interfering with each other.

 

Correct Answer: Option 2) Queuing delay

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Key Points:

Type of Delay	Description	Can It Be Zero?
Propagation Delay	Time taken for the signal to travel from sender to receiver, depends on distance and medium.	No — Even with one packet, propagation through medium takes time.
Queuing Delay	Time a packet waits in queue before transmission.	Yes — Since there’s no congestion or prior packet, the packet does not wait in queue.
Transmission Delay	Time to push the packet’s bits onto the wire, depends on packet size and bandwidth.	No — Even a single packet requires transmission time.
Processing Delay	Time required for routers/switches to examine the packet and make forwarding decisions.	No — Some processing is always required.

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Additional Information:

• Queuing delay can be zero when the network is idle or lightly loaded, as there is no waiting for the packet to be forwarded.
• Propagation, Transmission, and Processing delays are dependent on physical, hardware, and logical operations, and are rarely zero.

Conclusion: In a no-congestion environment with only one packet (P), only queuing delay can be considered zero.

A network hub is a hardware device for connecting multiple devices together and making them act as a single private network segment. It has multiple input/output (I/O) ports, in which a signal introduced at the input of any port appears at the output of every port except the original incoming. A hub works at the physical layer (layer 1) of the OSI model.

The correct answer is Telnet.

Key Points

• Any application that empowers users to remotely access another computer(no matter how far away) is called remote access.
• Telnet is an application protocol that uses a virtual terminal connection to offer bidirectional interactive text-oriented communication over the Internet.
• Telnet facilitates remote login on a computer.
• It also facilitates terminal emulation purposes.
• Telnet was developed in 1969.
• Telnet allows users to execute various application programmes on a distant site and then transport the results back to their local computer.

Additional Information

• The Hypertext Transfer Protocol (HTTP) is the backbone of the internet's data transfer.
  • It is a stateless protocol.
• Real-Time Protocol (RTP) is a protocol designed to handle real-time traffic (like audio and video) of the Internet.
• File Transfer Protocol is a set of rules that govern how computers transfer files from one system to another over the internet

The correct answer is option 4.

Concept:

The bridge is used to connect similar LANs with the same protocols. A bridge operates at the data link layer. It is also used for interconnecting two LANs working on the same protocol. It has a single input and single output port, thus making it a 2 port device. A bridge must contain addressing and routing capability.

A bridge is a network device that joins two or more LANs (local area networks) to build a larger LAN. Network bridging is the process of aggregating networks. A bridge joins the various components to make them appear as if they are all part of the same network.

Hence the correct answer is Bridges.

Additional Information

• Switches are networking devices that operate at the OSI model's layer 2 or data link layer. They connect network devices and use packet switching to deliver, receive, and forward data packets or data frames across the network. A switch has a number of ports into which computers can be connected.
• A router is a networking device that sends data packets from one computer network to another. On the Internet, routers are in charge of traffic direction. Data packets are used to send data over the internet, such as a web page or an email.
• A gateway is a network node that serves as a connection point between two networks that use distinct transmission protocols.

The Mesh network topology provides the highest fault tolerance of all of the network topologies. By having separate cables for each connection, it allows any one cable to break without interfering with the rest of the network.

Given:

Message size = 2400 bits.

The header of the transport layer = 150 bits.

Segment size at transport layer = (Header + Message size) = 150 + 2400 = 2550 bits.

Maximum, transmission unit at destination network = 900 bits

 So, At a time, data supported by the destination network = 900 – 26 = 874 bits.

Hence, 2550 bits are divided into packets having a maximum of 874 bits. So:

But 874 is not divisible by 8,

So, 

Length of packet 1 = 872 bits.

Length of packet 2 = 872 bits.

Length of packet 3 = 806 bits.

 

 

Total  = 2550 bits.

Network layer packets are transmitted via two networks, each of which uses a 26-bit header. So, The number of bits, including headers delivered to the destination network is:

Packet 1 (Data + Header) size = 26 + 26 + 872 = 924 bits.

Packet 2 (Data + Header) size = 26 + 26 + 872 = 924 bits.

Packet 3 (Data + Header) size = 26 + 26 + 806 = 858 bits.

 Total = 2706 bits. 

The correct answer is Gateway.

Key Points

• A device used to connect two or more different networks is called Gateway.
  • ​It is a network node used in telecommunications that connects two networks with different transmission protocols together.
  • It serves as an entry and exit point for a network as all data must pass through or communicate with the gateway prior to being routed.
  • It is also called as ' Protocol Converter ' because it can convert the data packets as per the destination network protocol requirement.
• Switches
  • ​A network switch forwards data packets between devices.
  • Switches are networking devices operating at layer 2 or a data link layer of the OSI model.
  • Switches can be hardware devices that manage physical networks or software-based virtual devices.
• Repeater
  • ​It operates at physical layer of the OSI model.
  • It is a hardware device that regenerates an incoming signal from the sender before retransmitting it to the receiver.
• Hub
  • ​A network hub is a node that broadcasts data to every computer or Ethernet-based device connected to it.
  •  A hub has many ports in it. They are generally used to connect computers in a LAN.

A media access control address (MAC address) is a unique identifier assigned to a network adaptor for use as a network address in communications within a network segment. This use is common in most IEEE 802 networking technologies, including Ethernet, Wi-Fi, and Bluetooth.

Important Points:

MAC broadcast address (MAC destination) consists of 6 bytes i.e. 48 bits and all are 1’s

MAC broadcast address → FF:FF:FF:FF:FF:FF

Limited broadcast address (IP-32 bit) → 255.255.255.255

The correct answer is option 3.

Concept:

MODEM stands for modulator-demodulator. A modem is a piece of hardware that allows a computer to send and receive data through a phone line, cable, or satellite.

• A modem is a device that sends and receives data through a communication channel like twisted-pair telephone lines, coaxial cables, or optical fibres.
• The modulation technique is used to transform the analogue signal to digital at the source.
• Demodulation is employed at the receiver to transform the digital signal back to the analogue.

Hence the correct answer is Modem.

OSI Model

• OSI stands for Open System Interconnection is a reference model that describes how information from a software application in one computer moves through a physical medium to the software application in another computer.
• OSI consists of seven layers, and each layer performs a particular network function.
• OSI model was developed by the International Organization for Standardization (ISO) in 1984, and it is now considered as an architectural model for inter-computer communications.

There are seven OSI layers. Each layer has different functions. A list of seven layers are given below:

1) Physical Layer: 

• The main functionality of the physical layer is to transmit the individual bits from one node to another node.
• It is the lowest layer of the OSI model.

2) Data-Link Layer: 

• This layer is responsible for the error-free transfer of data frames.
• It defines the format of the data on the network.
• It provides reliable and efficient communication between two or more devices.

3) Network Layer: 

• It is a layer 3 that manages device addressing, tracks the location of devices on the network.
• It determines the best path to move data from source to destination based on the network conditions, the priority of service, and other factors.
• Logical Addressing and Routing are functions of the Network Layer.

4) Transport Layer: 

• The Transport layer is a Layer 4 ensures that messages are transmitted in the order in which they are sent and there is no duplication of data.
• The main responsibility of the transport layer is to transfer the data completely.

5) Session Layer:

• The Session layer is used to establish, maintain, and synchronizes the interaction between communicating devices.

​6) Presentation Layer:

• It acts as a data translator for a network.
• This layer is a part of the operating system that converts the data from one presentation format to another format.

7) Application Layer: 

• An application layer serves as a window for users and application processes to access network service.
• This layer provides network services to the end-users.
• HTTP is an application layer protocol designed within the framework of the Internet protocol suite. Its definition presumes an underlying and reliable transport layer protocol, and Transmission Control Protocol (TCP) is commonly used.

​Thus, HTTP is an application layer in the OSI Model of Networking.

Key Points

Network layer protocols are,

• IP(Internet Protocol​),
• ARP(Address Resolution Protocol),
• ICMP (Internet Control Message Protocol).

Hence the correct answer is IP.

Additional Information

• SMTP (Simple Mail Transfer Protocol) is an application layer protocol in OSI.
• HyperText Transfer Protocol (HTTP), is the Web's application-layer protocol,
• Transmission Control Protocol (TCP) In terms of the OSI model, TCP is a transport-layer protocol.