Computer Networking 2

Better

💡 What is a Computer Network?

when two or more computers are connected to share resources such as files, data, and printers.

🔌 Ethernet

• a group of technologies used to create wired networks.

• It is the most common type of network connection today.

• Proper name: IEEE 802.3

📶 Wi-Fi

• group of technologies used to create wireless networks that send data using radio waves.

• Proper name: IEEE 802.11

• very popular and widely used.

⚙ Other Network Signaling Types

Token Ring: Expensive and uses proprietary licenses.

Arcnet: Older and slower alternative to Ethernet.

🌐 Protocols

set of rules that all computers follow to communicate properly.

Examples of Protocols

• TCP: Transmission Control Protocol

• IP: Internet Protocol

• HTTP: HyperText Transfer Protocol

• FTP: File Transfer Protocol

• SMTP: Simple Mail Transfer Protocol

🕸 Network Types

• LAN (Local Area Network): A private network within one building.

• MAN (Metropolitan Area Network): Covers a city or town (less common term).

• WAN (Wide Area Network): Connects multiple LANs or MANs across large distances.

• PAN (Personal Area Network): Small network for personal devices like phones and laptops.

• HAN (Home Area Network): Used in homes to connect TVs, computers, and other devices.

💻 What’s on a Network

• Node: Any connection point on a network.

• Host: A computer connected to the network.

• Device: Hardware used to build or support the network.

🔄 Peer-to-Peer (P2P) Network

• Two or more computers share resources directly with each other.

• Used in small networks like home setups.

• Each computer controls what it shares.

💻 Client-Server Network

• One main computer (server) stores data and manages devices.

• Other computers (clients) connect to it to use those resources.

• This setup is common in businesses.

🗺 Network Topology

the physical layout showing how computers are connected (like star, ring, or bus).

👩‍💻 Client

regular desktop or laptop computer that a user works on.

🧩 Network Interface Card (NIC)

• connects a computer to a network.

• It converts digital data into signals for sending and receiving.

• Most modern computers have it built into the motherboard.

🧵 Network Cables

• Used to connect devices in a LAN.

• The most common type is Twisted Pair Cable (RJ-45 connector).

Types of Cables:

• UTP (Unshielded Twisted Pair): Twisted wires reduce interference.

• STP / SF/FTP: Shielded cables with extra protection.

• Cat5, Cat5e, Cat6: Categories showing speed and performance level.

• Best type: SF/FTP (most shielded and best performance).

🌈 Fiber Optic Cable

Uses light signals through glass or plastic fibers to send data.

Pros of Fiber Optic Cable:

• Very fast

• Secure

• No interference

• Not flammable

Cons of Fiber Optic Cable:

• Expensive

• Hard to repair

⚙ Hub

• connects multiple computers together.

• When one sends data, all others receive it.

• It is simple but not efficient.

🔀 Switch

• connects multiple computers but sends data only to the correct destination.

• It is faster and more efficient than a hub.

🌍 Router

• connects different networks together (for example, home network to the internet).

• It directs traffic and can be wired or wireless.

• This is what other networks “see” when you connect to the internet.

📡 Wireless Devices

• Only NICs and Routers can be

• Wi-Fi standards are based on 802.11.

• Wi-Fi speeds depend on both connected devices.

📦 Network Data Packet (Data Frame)

• Data on a network is sent in small units called packets.

• Each packet includes extra information like source, destination, and error checking.

Main Parts of a Data Frame:

• Frame Control: Identifies type and security.

• Duration: How long the channel will be used.

• MAC Address Fields: Shows sender, receiver, and destination.

• Sequence Control: Helps put data back in order.

• Data Payload: The actual data being sent.

• Frame Check Sequence (FCS): Detects transmission errors.

🧠 MAC Address

• Every device on a network has a unique Media Access Control address.

• Example: 00:1A:2B:3C:4D:5E

• It identifies devices locally on the network.

🌐 IP Address (IPv4)

• is a 32-bit number that uniquely identifies a device on a network.

• Example: 192.168.123.132

• It has two parts: Network ID and Host ID.

✂ Why Subdivide Networks (Subnetting)?

1. Improve performance

2. Reduce congestion

3. Increase security

4. Control growth

5. Make management easier