Understanding Computer Networks: Types, Components, and Protocols

Understanding Computer Networks

A computer network is a set of computers connected to each other, enabling them to share resources and exchange information. They can share printers, files, folders, and Internet connections.

Ethernet Classification

The two common types of Ethernet networks are 100Base-T and 1000Base-T.

The number indicates the transmission speed in Megabits per second: 100Mbps and 1000Mbps, respectively.

The letter 'T' indicates the type of cable used to transmit data. The cable consists of twisted pairs of copper wire with RJ45 connectors at each end. These cables are used to connect the network.

Types of Cables

• Twisted Pair UTP: 8 copper wires twisted together in 4 pairs with an RJ45 connector at the end.
• STP: A safer cable for transmitting data.
• Fiber Optic Cable: Cable containing optical fibers used to carry light. They permit transmission over longer distances and at higher bandwidths than wire cables. There are two types: Multi-mode and Single-mode.

Types of Wireless Networks

Wireless networks, or WLANs (Wireless Local Area Networks), do not use wires.

• Wi-Fi Technology: The elements used are:
  • A wireless router: Converts the phone line into radio signals.
  • A wireless access point (WAP).
• Bluetooth Technology: Uses short-wavelength UHF radio waves.

Elements of a LAN

• Network Card: An electronic device that connects a computer to a computer network, usually a LAN.
• Hubs: Passive network elements with a series of RJ45 ports.
• Switches: Active network elements.
• Routers: Small physical devices that join multiple networks together.

TCP/IP Protocol

TCP/IP allows communication among computers with different operating systems and different types of communication. This protocol is used by the Internet.

IP Address Classification

• Class A: Used in large networks (Internet servers). It supports only 126 networks. The first group ranges from 1 to 126.
• Class B: Used for medium-sized networks (big companies around the world). It supports 16,384 networks. The first group ranges from 128 to 191.
• Class C: Used in small networks (LANs and intranets). It supports 2,097,152 networks. The first group ranges from 192 to 223.

Switches vs. Hubs

A switch is more modern and faster because data is transmitted directly between the two nodes or computers involved.

What is an IP Address?

An IP address is a number that identifies each computer on a network. It consists of 4 sets of numbers between 0 and 255.