Networking: PAN and LAN

• Networking is the interconnection of devices, such as computers, smartphones, and printers, enabling them to communicate and share resources like files, printers, and internet access

Types of Networks

• Networks are classified based on geographical spread and purpose

Personal Area Network (PAN)

• A PAN is the smallest network type, covering a limited area, typically around one person
• PANs involve devices like smartphones, laptops, and Bluetooth headsets
• Wireless headphones connecting to a phone is an example
• PANs are easy to set up and manage, and are of low cost
• PANs disadvantages include limited range and bandwidth

Local Area Network (LAN)

• A LAN connects devices within a limited area like a home, school, or office building
• A school computer lab or an office network are examples of LANs
• LANs offer high data transfer speeds, easy file and resource sharing and are relatively low cost to set up
• LAN disadvantages include a limited geographical area and potential security issues if not properly managed

Campus Area Network (CAN)

• A CAN connects multiple LANs within a limited geographical area, like a university campus, a large school, or a group of buildings
• A network connecting different departments in a university gives an example of a CAN
• CAN advantages include a larger coverage area than a LAN, as well as improved communication and resource sharing within the campus
• CAN disadvantages include being more complex to set up and manage than a LAN, and they have a higher cost compared to a LAN

Metropolitan Area Network (MAN)

• A MAN covers a larger area than a LAN, such as a city or a metropolitan region
• MANs are often used by large organizations or service providers
• A cable TV network or a network connecting different branches of a company within a city are examples of MANs
• MANs have a larger coverage area than a LAN or CAN, and they offer efficient communication within a city or region
• MAN disadvantages include higher costs compared to LANs, and more complex management and maintenance

Wide Area Network (WAN)

• A WAN spans a large geographical area, often covering countries or even continents
• The internet is the largest example of a WAN
• WANs offer the largest coverage area and enable global communication and information sharing
• WAN disadvantages include lower data transfer speeds compared to LANs, higher costs and more complex management, and security concerns from its vastness

Networking Components

• Networks involve various hardware and software components working together to enable communication between devices

Network Interface Card (NIC)

• An NIC, also known as a network adapter or network card, is a hardware component that allows a device (like a computer) to connect to a network
• The NIC provides the physical interface between the device and the network medium (like a cable or wireless signal)
• An NIC prepares data for transmission over the network and receives incoming data with a unique MAC (Media Access Control) address to identify the device on the network

Cables and Connectors

• Cables are physical media used to transmit data between devices in a wired network
• Connectors are used to attach cables to devices and networking hardware

Types of Cables

• Twisted-Pair Cable: Consists of pairs of wires twisted together to reduce interference, such as Ethernet cables like Cat5, Cat5e, Cat6
• Coaxial Cable: This cable has a central conductor surrounded by insulation and a metallic shield, used for cable TV and older network connections
• Fiber Optic Cable: Transmits data as light pulses through thin glass or plastic fibers offering high bandwidth and long-distance transmission

Hubs

• A hub is a simple networking device that connects multiple devices in a network and acts as a central connection point
• When a hub receives data from one device, it broadcasts that data to all other connected devices
• Hubs create much network traffic (collisions) because all devices share the same bandwidth and are less secure because all devices receive all data
• Hubs are largely outdated and replaced by switches

Switches

• A switch is a more intelligent networking device than a hub, which also connects multiple devices but operates more efficiently
• A switch learns the MAC addresses of connected devices and forwards data only to the intended recipient, which reduces network traffic and improves performance
• Switches reduce network collisions, improve network performance, and are more secure than hubs

Routers

• A router is a networking device that connects different networks together forwarding data packets between networks
• Routers determine the best path for data to travel between networks using IP addresses to route traffic and provide security features like firewalls
• A home router connecting a home network to the internet is an example of a router

Modems

• A modem (Modulator-Demodulator) converts digital signals from a computer into analog signals for transmission over a communication medium (like telephone lines or cable TV lines) and vice versa
• A modem allows computers to connect to the internet through various internet service providers (ISPs)

Network Topology

• Network topology refers to the physical or logical arrangement of devices and connections in a network
• Topologies define how devices are interconnected and how data flows between them
• The choice of topology affects network performance, cost, and ease of management

Bus Topology

• In a bus topology, all devices are connected to a single central cable called the "bus" or "backbone"
• Data is transmitted along this cable, and all devices can "see" the data, but only the intended recipient accepts it
• This topology is simple to set up and requires less cable than other topologies, and is cost-effective for small networks
• The entire network goes down if the main cable breaks, performance degrades as more devices are added because of increased traffic/collisions, and is difficult to troubleshoot problems

Star Topology

• In a star topology, all devices are connected to a central hub or switch
• All communication between devices passes through this central point
• It is easy to install and manage, and if one device or cable fails, it doesn't affect the remainder of the network, with easy troubleshooting
• It requires more cable than a bus topology, and the entwork goes down if the hub/switch fails

Ring Topology

• In a ring topology, each device connects to two other devices, forming a closed loop or ring with data traveling in one direction around the ring
• Data traveling in one direction reduces the chance of collisions and performs well under heavy network loads in Ring topologies
• The entire network can be affected if one device or cable fails making troubleshooting difficult, and adding/removing devices can disrupt the network

Mesh Topology

• In a mesh topology, each device connects to multiple other devices, creating redundant paths for data to travel
• Mesh topologies are highly reliable because there are multiple paths for data to travel, and if one path fails, data can be rerouted through another path.
• This set up is expensive to implement due to the large amount of cabling required and it is complex to set up and manage

Tree Topology

• A tree topology combines characteristics of bus and star topologies with a main cable (trunk) and branches of star networks connected to it
• Since it is scalable and flexible, it is easy to expand the network
• If the main cable (trunk) fails, entire sections of the network can be affected and it is more complex to manage than simpler topologies