3.4 | NETWORK HARDWARE

Topics from the Cambridge IGCSE (9-1) Computer Science 0984 syllabus 2023 - 2025.

OBJECTIVES
3.4.1 Understand that a computer needs a network interface card (NIC) to access a network
3.4.2 Understand what is meant by and the purpose of a media access control (MAC) address, including its structure
3.4.3 (a) Understand what is meant by and the purpose of an internet protocol (IP) address
(b) Understand that there are different types of IP address
3.4.4 ​Describe the role of a router in a network

ALSO IN THIS TOPIC
3.1.1 COMPUTER ARCHITECTURE 
3.1.2 COMPUTER ARCHITECTURE 
​3.1.3 COMPUTER ARCHITECTURE 
​3.1.4 COMPUTER ARCHITECTURE 
3.1.5 COMPUTER ARCHITECTURE 
​3.2.1 INPUT AND OUTPUT DEVICES 
 ​3.2.2 INPUT AND OUTPUT DEVICES 
3.2.3 INPUT AND OUTPUT DEVICES
​3.3 DATA STORAGE 
YOU ARE HERE | ​3.4 NETWORK HARDWARE 
REVISION CARDS
TOPIC 3 KEY TERMINOLOGY
TOPIC 3 ANSWERS
TOPIC 3 TEACHER RESOURCES
TOPIC 1 TEACHER RESOURCES (CIE)

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NETWORK INTERFACE CARD (NIC)

The NIC (Network Interface Card) is a hardware component that allows a computer to connect to a network. Its purpose is to enable communication between a computer and other devices on a network, such as other computers, servers, printers, or routers.

The NIC typically provides a physical connection to the network, such as through an Ethernet cable or Wi-Fi signal, and it also provides the necessary protocols and software to transmit and receive data over the network. The NIC converts the digital data from the computer into signals that can be transmitted over the network, and it also receives incoming signals and converts them into digital data that the computer can understand.

The purpose of the NIC is to facilitate network communication by providing a physical connection and the necessary software and protocols to transmit and receive data over the network.

MEDIA ACCESS CONTROL

A Media Access Control (MAC) address is a unique identifier assigned to a network interface controller (NIC) by the manufacturer. It is used to identify devices on a network, and it is essential for communication between devices at the data link layer of the OSI (Open Systems Interconnection) model.

The purpose of the MAC address is to provide a unique identifier to each device connected to a network, allowing devices to send and receive data to and from other devices on the same network. When a device needs to send data over the network, it uses the MAC address to locate the destination device.

The structure of a MAC address consists of six pairs of hexadecimal digits (0-9, A-F), separated by colons or hyphens. The first three pairs represent the manufacturer's unique identifier, while the last three pairs represent the unique identifier assigned to the specific device by the manufacturer. This structure allows for over 281 trillion possible MAC addresses, ensuring that every device on a network has a unique identifier.

For example, a MAC address might look like this: 00-1A-2B-3C-4D-5E. In this example, the first three pairs (00-1A-2B) represent the manufacturer's unique identifier, while the last three pairs (3C-4D-5E) represent the device unique identifier assigned to the specific device by the manufacturer.

INTERNET PROTOCOL (IP)

An IP address is a unique identifier assigned to each device connected to the internet. It is similar to a physical mailing address, in that it allows devices to be identified and located on the internet. Without IP addresses, devices would not be able to communicate with each other over the internet.

When a device sends a request to access a resource on the internet, such as a website or a file, its IP address is included in the request. The router then uses this IP address to route the request to the appropriate destination. The IP address is used to identify the specific device that made the request and to ensure that the response is sent back to the correct device.

IP addresses are assigned by Internet Service Providers (ISPs) and are typically assigned dynamically, meaning they may change over time. However, devices can also be assigned a static IP address, which remains the same over time. Static IP addresses are typically used for devices that need to be reachable from the internet at all times, such as web servers or email servers.

IP addresses are crucial for devices to communicate with each other over the internet. They allow routers to direct traffic to the correct destination and ensure that responses are sent back to the correct device.

PARTS OF THE IP ADDRESS

The structure of an IP address consists of four numbers separated by periods, with each number ranging from 0 to 255. For example, an IP address might look like this: 192.168.1.1. This particular IP address is often used as the default address for a router.

There are two types of IP addresses: IPv4 and IPv6. IPv4 addresses are the older of the two and consist of 32 bits, and is represented in 4 section for example 192.168.1.1 allowing for approximately 4.3 billion unique addresses. IPv6 addresses are newer and consist of 128 bits,  typically written in eight groups of four hexadecimal digits separated by colons, for example 2001:0db8:85a3:0000:0000:8a2e:0370:7334 allowing for trillions of unique addresses.

In summary, the purpose of an IP address is to provide a unique identifier for each device connected to the internet, allowing for communication and traffic routing between devices on the internet.

THE ROUTER

A router is a networking device that connects multiple networks and directs network traffic between them. Its primary role is to forward data packets between networks based on their IP addresses.

When a device sends data over a network, it is transmitted in the form of data packets. Each data packet includes the IP address of the destination device, and the router uses this information to determine where to send the packet next. The router may also use other factors, such as network congestion or network topology, to optimize the routing of data packets.

A router may also perform other functions, such as:

• Providing network address translation (NAT) to allow multiple devices on a private network to share a single public IP address. NAT allows devices on a private network to communicate with devices on the internet, while still keeping the private network hidden from external networks.
• Providing security features such as firewalls to protect the network from unauthorized access and attacks.
• Providing quality of service (QoS) features to prioritize certain types of network traffic, such as video or voice data, to ensure that they receive sufficient bandwidth and are not affected by network congestion.
• Providing wireless access points to allow wireless devices to connect to the network.

Many networks now use Access points, the main difference between a router and an access point is that a router is a device that connects multiple networks and directs traffic between them including forwarding data packets between networks based on their IP addresses, while an access point is a device that enables wireless devices to connect to a wired network.

The role of a router in a network is to facilitate communication between multiple networks by forwarding data packets between them. It plays a critical role in ensuring that data is transmitted efficiently and securely across the network.

​1: What is the purpose of a MAC address, and how is it used in network communication?
2: Explain the structure of an IP address, including how the network ID and host ID are used in routing data packets.
3: Describe the role of a router in a network, and give an example of a situation where a router might be used.
4: What is the difference between a static IP address and a dynamic IP address, and what are the advantages and disadvantages of each?
5: How does network address translation (NAT) work, and what is its purpose?
6: What is an access point, and how does it enable wireless devices to connect to a wired network?

NAVIGATION

3.1.1 COMPUTER ARCHITECTURE | The role of the CPU
3.1.2 COMPUTER ARCHITECTURE | Components of the CPU
3.1.3 COMPUTER ARCHITECTURE | Core's, Cache and Clock speed
3.1.4 COMPUTER ARCHITECTURE(CIE) | The Instruction Set
3.1.5 COMPUTER ARCHITECTURE | Embedded Systems
3.2.1 INPUT AND OUTPUT DEVICES | Input Devices
3.2.2 INPUT AND OUTPUT DEVICES | Output Devices
3.2.3 INPUT AND OUTPUT DEVICES | Sensors
3.3 DATA STORAGE | Primary, Secondary, Virtual and Cloud storage
3.4 NETWORK HARDWARE | Networks, Components and Protocols
REVISION CARDS | Flip cards to help test yourself
TOPIC 3 KEY TERMINOLOGY
TOPIC 3 ANSWERS
TOPIC 3 TEACHER RESOURCES