LANs and WANs Networking

• Networking facilitates quick file transfers and shared access to peripherals
• Networks enable accessing files from any connected computer
• Centralized control over security, software, and backups is managed via a server
• Communication through email and social media enhances collaboration

Local Area Network (LAN)

• LANs cover single sites within small geographical areas
• Organizations own all LAN hardware
• LANs are wired with UTP or fiber optic cables, or use Wi-Fi

Wide Area Network (WAN)

• WANs connect LANs over large geographical areas
• Infrastructure is leased from telecommunication companies
• WANs are connected via telephone lines, fiber optic cables, or satellite links

Routers

• Home routers are multi-functional devices integrating switch, router, and wireless access point functionalities

Bandwidth

• Bandwidth: the volume of data transferable in a set period
• Bandwidth measures data quantity transmitted, not speed
• Bandwidth is measured in bits per second (bit rate)

Number of Users

• Excessive users/devices on a network with limited bandwidth can reduce network speed

Transmission Media

• Wired offer higher bandwidth than wireless
• Fibre optic cables provide better bandwidth than copper ones

Error Rate

• Unreliable increase errors during data transfer
• Data must be resent until correctly received
• Wireless connection quality depends on distance from access point and environmental factors
• Copper cable signal quality relies on material grade, with higher grades reducing interference
• Cable length also affects signal quality

Latency

• Latency is the delay between data transmission and reception, caused by network bottlenecks
• Bottlenecks include improper traffic segmentation and mismatched hardware speeds

Server

• Controls access and security to a shared file store
• Server manages internet access and printing jobs
• Provides email services and runs data backups

Client

• A client sends requests to the server

Server Advantages

• Managing security is easier
• Backing up shared data is simplified
• Software updates are easier to install

Server Disadvantages

• Setup and maintenance are expensive
• Requires IT specialists
• Failure creates a single point of failure
• Users lose access if server fails

Peer-to-peer Model

• All computers (peers) on the network are equal
• Peers share files with each other
• Individual peers handle security and backups
• Each peer usually has their own printers

Peer-to-peer Advantages

• Very easy to maintain
• Specialist staff not needed
• No dependency on a single computer
• It is cheaper and has no expensive hardware

Peer-to-peer Disadvantages

• Less secure
• Users must manage own backups
• Difficult to maintain a well-ordered file store

The Internet

• The Internet is the largest WAN
• A global collection of interconnected networks
• Distinct from the World Wide Web, which is a service on the Internet

Home Network Configuration

• A home network connects via a wireless router
• The router connects to an Internet Service Provider (ISP) via telephone or fibre optic cable
• The ISP links to a Domain Name Server (DNS) and other routers on the internet backbone
• Those routers also connect to LANs, Routers, and Servers.

Web Servers and Clients

• Hosting websites and handling client requests are common functions
• Websites are sent as text files (HTML, CSS, JavaScript) to a browser, which renders them

Web Page Request Process:

• The client enters a URL in a web browser
• The browser sends the domain name to a Domain Name Server (DNS)
• The DNS maps the domain name to an IP address and returns it to the browser
• A GET request for the web page is sent to the web server using its IP address
• The requested web page returns to the client's web browser

The Cloud

• Cloud involves using server networks to store data and programs accessible over the internet

Cloud Advantages

• Access is available anytime, anywhere, from any device
• It has large storage capacity
• Automatic backup
• Simple to collaborate