Understanding Network Protocols and Addressing

Protocols

Rules that govern communication, determining how it is made and managing factors like transmission speed and error checking.

Internet Protocol (IP) addressing

A method of assigning a unique IP address to each device on a network, consisting of four sets of up to three digits separated by dots.

Node

A device on a network that can send or receive messages.

Switch

A network device that routes messages to the correct node based on its address.

Static address

An IP address that remains the same each time a device connects to the network.

Dynamic address

An IP address that changes each time a device connects to the network, assigned by a method known as dynamic host configuration protocol (DHCP).

Dynamic Host Configuration Protocol (DHCP)

A method that assigns dynamic IP addresses to devices each time they connect to a network.

IPv4

An addressing method that uses four sets of digits, allowing for up to 4.3 billion addresses (4,300,000,000).

IPv6

A newer addressing method that uses eight sets of four-digit hexadecimal values, allowing for approximately 340 trillion trillion trillion addresses.

MAC addressing

A method of assigning a unique serial number (MAC address) to each network interface controller (NIC) to identify devices on a network.

Network Interface Controller (NIC)

A hardware component that connects a device to a network and has a unique MAC address.

MAC address

A unique string of hexadecimal numbers assigned by the NIC's manufacturer that cannot be changed.

TCP/IP

Transmission Control Protocol/Internet Protocol, which enables communication over the internet.

HTTP

Hypertext Transfer Protocol, which governs communication between a web server and a client.

HTTPS

Hypertext Transfer Protocol Secure, which includes encryption for secure transactions over the internet.

FTP

File Transfer Protocol, which governs the transmission of files across a network and the internet.

SMTP

Simple Mail Transfer Protocol, which governs the sending of email over a network to a mail server.

Hexadecimal

A base-16 number system used in MAC addresses, consisting of digits 0-9 and letters A-F.

POP

Post Office Protocol, an older implementation for retrieving emails from email servers.

IMAP

Internet Message Access Protocol, a newer implementation that largely replaces POP for retrieving emails.

Layering

The concept of breaking up the sending of messages into separate components and activities in networking.

TCP/IP model

A model that describes the layering of networking communication.

Application layer

The layer that encodes/decodes the message in a form that is understood by the sender and the recipient.

Transport layer

The layer that breaks down the message into small chunks (packets) and assigns packet numbers.

Network layer

The layer that adds the sender's IP address and that of the recipient to the message.

Link layer

The layer that enables the transfer of packets between nodes on a network and between different networks.

IP address

A unique address assigned to each device on a network, used for sending and receiving messages.

Nodes

Devices on a network that can send, receive, or forward information.

Standards

Established norms that allow for the development and adaptation of hardware and software over time.

Plaintext

Unencrypted messages that are readable and understandable.

Ciphertext

Encrypted messages that cannot be understood without decryption.

Caesar cipher

A simple method of encryption that replaces each plaintext letter with another letter a fixed number of positions down the alphabet.

Algorithms

Complex methods used in real-life encryption to secure messages.

Asymmetric encryption

A method that uses a public key and a private key for encryption, allowing secure communication.

Public key

A key that can be shared with anyone to encrypt messages.

Private key

A secret key used to decrypt messages that were encrypted with the corresponding public key.

Public Key

A key that cannot decrypt a message; only the private key can do that.

Private Key

The key that can decrypt a message and must never be given out to maintain encryption.

Online Banking

A service that uses public and private keys for secure communication between users and banks.

Encryption

The process of converting information into a code to prevent unauthorized access.

Wired Networks

Networks that use physical wiring to connect devices, often used in office settings.

Wireless Networks

Networks that use radio waves to carry signals, allowing mobile devices to connect within range.

Maximum Transmission Speed for Ethernet

Up to 1 gigabit per second.

Maximum Transmission Speed for Wireless Networks

Up to 50 megabits per second.

Maximum Distance for Reliable Communication for Ethernet

Up to 100 metres for Ethernet and over 2 kilometres for fibre optic.

Maximum Distance for Reliable Communication for Wireless Networks

Up to 50 metres.

Security of Wired Connection

More secure as a physical connection is required to intercept data.

Security of Wireless Connection

Less secure as the wireless signal cannot be contained within a building.

Advantages of Wi-Fi

Allows setting up LANs without wires and enables users to log in from anywhere within the Wi-Fi network.

Disadvantages of Wi-Fi

Signal strength weakens with distance from the router and may not be as secure as wired connections.

Bluetooth

A form of wireless communication that enables devices to connect and share data.

Bluetooth Transmission Speed

Often only up to 2 megabits per second.

Advantages of Bluetooth

Low cost to set up and uses relatively little power.

Disadvantages of Bluetooth

Short range, low level of security, and low data transmission rate.

Encryption in Online Purchases

Online purchases are encrypted to prevent theft of credit card details.

Encryption for Document Sharing

Tools enable users to encrypt documents before sending them via the internet.

Encrypted Satellite TV Transmissions

Transmissions are encrypted to prevent non-subscribers from watching shows.