Question 1
a) Define the term computer network using examples.
b) Identify and distinguish 3 types of computer networks.
c) Identify and distinguish 4 network topologies. Use diagrams to illustrate your answer.
Question 2
a) Define the term node addressing methods.
b) Outline the following features of node addressing methods;
Circuit switching
Message switching
Packet switching
Frame relay
Cell relay
Question 3
a) Explain channel utilization techniques and their features.
b) Explain CSMA/CA as a principle of access protocols.
Question 4
Thabo is an intern at a company specialising in computer networking systems. His team has been given a new project to plan and implement the LAN network for a top auditing firm. Sam, Thabo's mentor has requested Thabo to identify all the LAN components. Assist Thabo to identify and describe the purpose of LAN components.
Question 5
a) Describe circuit switching and packet switching.
b) Identify the differences between switching and packet switching techniques.
Question 1
a) A computer network is a group of interconnected computers and devices that can communicate with each other. This enables sharing of resources such as files, printers, and internet access. Examples of computer networks include LANs (Local Area Networks), WANs (Wide Area Networks), and the Internet.
b) Three types of computer networks are:
1. LAN (Local Area Network): A LAN is a network that covers a small geographical area, typically within a single building or campus. It is used for connecting devices within a limited area, such as a home or office.
2. WAN (Wide Area Network): A WAN is a network that covers a broad area, such as a city, country, or even globally. It connects multiple LANs and allows for communication over long distances.
3. WLAN (Wireless Local Area Network): A WLAN is a type of LAN that uses wireless technology to connect devices instead of traditional wired connections.
c) Four network topologies are:
1. Bus Topology: In this topology, all devices are connected to a single central cable called a bus. Data is transmitted through the bus, and all devices receive the data, but only the intended device processes it.
2. Star Topology: In this topology, all devices are connected to a central hub or switch. Data is transmitted through the hub, and only the intended device receives and processes the data.
3. Ring Topology: In this topology, devices are connected in a circular fashion, where each device is connected to two other devices. Data travels in a ring, passing through each device until it reaches the intended recipient.
4. Mesh Topology: In this topology, each device is connected to every other device in the network. This provides redundancy and multiple paths for data to travel, increasing reliability.
Question 2
a) Node addressing methods refer to the techniques used to assign unique identifiers to nodes (devices) in a network to enable communication.
b) Features of node addressing methods:
- Circuit Switching: Establishes a dedicated communication path between nodes before data transmission. The path remains active until the communication is completed.
- Message Switching: Data is divided into blocks (messages) and sent through the network. Each message is routed individually based on destination address.
- Packet Switching: Data is divided into packets, which are sent separately through the network and reassembled at the destination.
- Frame Relay: A high-speed packet-switching technology that operates at the data link layer of the OSI model and is used in wide area networks.
- Cell Relay: A form of packet switching that uses fixed-length cells for data transmission.
Question 3
a) Channel utilization techniques are methods used to ensure efficient use of the available communication channels in a network. Features of these techniques include:
- Multiplexing: Allows multiple users to share a single communication channel by dividing the channel into multiple smaller channels.
- Spread Spectrum: Spreads the signal over a broad frequency range to reduce interference and increase security.
- Frequency Division Multiplexing: Divides the frequency spectrum into separate channels for transmitting data simultaneously.
- Time Division Multiplexing: Divides the time into fixed intervals for transmitting data from multiple sources.
b) CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) is a protocol used in wireless networks to reduce collisions by allowing nodes to listen to the network before transmitting data. Nodes must wait for a clear channel before sending data to avoid collisions.
Question 4
Some LAN components and their purposes are:
- Switches: Devices that connect multiple devices within a LAN and manage data traffic.
- Routers: Devices that connect multiple LANs and route data between them.
- Network Interface Cards (NICs): Hardware components that enable devices to connect to a network.
- Cables: Used to physically connect devices within the LAN.
- Servers: Store and manage data, provide services, and control access to resources within the LAN.
Question 5
a) Circuit switching involves establishing a dedicated communication path between devices before data transmission, while packet switching involves dividing data into packets that are sent separately through the network.
b) Differences between the two techniques include:
- Circuit switching requires the establishment of a dedicated path for communication, while packet switching does not.
- Circuit switching is more suitable for voice communication, while packet switching is more efficient for data transmission.
- Circuit switching has a fixed bandwidth allocation, while packet switching dynamically assigns bandwidth based on network conditions.