Fundamentals of Networking

• This module covers computer system servicing (CSS) under the Information and Communications Technology (ICT) Course.
• It aims to enhance understanding of installing and configuring computer systems.
• The learning competency is to install network cables (TLE_IACSS9-12SUCN-IVa-j-33)
• Subtasks include defining networking concepts, identifying network media, and describing networking devices and testing devices.

Fundamentals of Networking

• A computer network involves two or more interconnected computer systems.
• Connections can utilize cable or wireless media.
• Computer networks are advantageous in: connecting multiple computers for information exchange, printer and scanner sharing, fast information sharing, and efficient/less expensive electronic communication

Computer Network Components

• Servers are computers that hold shared programs, files, and the network operating system.
• Servers provide network resource access to all users
• Clients are computer devices that access and use the network, sharing network resources and are also users able to send/receive requests from the server
• Transmission Media is the carrier used to interconnect computers in a network, known as links, channels or lines and includes coaxial cable, twisted-pair wire, and optical fiber cable
• Shared Data is data shared between clients, including data files, printer access programs, and email.
• Network Interface Card sends, receives data, and controls data flow between the computer and the network.
• Local Operating System helps personal computers access files and local printers, using one or more disk/CD drives on the computer.
• Network Operating System operates on computers and servers to allows the computers to communicate via the network
• Protocol: set of rules for entities to communicate across a network; includes IP, TCP, UDP, FTP
• OSI: Open Systems Interconnection model to specify standards for communications

Unique Identifiers of a Network

• Hostname: unique name associated with each device on the network.
• IP Address: unique identifier for each device; 32 bits for IPv4 and 64 bits for IPv6.
• DNS Server: server that translates URLs (web addresses) into IP addresses.
• MAC Address: unique physical address of a NIC (Network Interface Card), with a general length of 12 digits, 6 bytes, or 48 bits
• Port: logical channel for sending/receiving data to an application, identified using port numbers
• ARP (Address Resolution Protocol): helps network users convert IP addresses into Physical Addresses
• RARP (Reverse Address Resolution Protocol): provides an IP address of the device with a given physical address as input

Uses of Computer Networks

• Sharing resources such as printers.
• Sharing expensive software and databases among participants.
• Fast and effective communication between computers.
• Exchanging data and information among users over a network.

Disadvantages of Computer Networks

• High initial costs for hardware and software.
• Security risks to data if proper precautions (encryption, firewalls) aren't taken.
• Network components may become outdated or malfunction, needing replacement.
• Networks require ongoing administration
• Frequent server failures and cable related issues are common

Types of Networks

• LAN (Local Area Network): Small network in a limited geographical area (e.g., a building).
• WAN (Wide Area Network): Computer network covering a broad area regionally or nationally.
• The Internet is the largest WAN
• MAN (Metropolitan Area Network): Hybrid between LAN and WAN, connecting two or more LANs in the same geographic area
• The Internet: A network of interconnected devices linked by electronic, wireless, and optical technologies.
• VPN (Virtual Private Network): Private network within a public infrastructure; uses a secure "tunnel" across the Internet for remote workers or offices to share data.
• Server-Based Network: Divides processing tasks between the client computer and the server.
• Client/server setup efficiently provides databases, management of applications, network management and centralized file storage
• Peer-to-Peer (P2P) Network: Each computer acts as both a server and a client, with no hierarchy; Examples include Skype and BitTorrent.

Network Media

• Network media is the physical path for electrical signals to travel between components.
• Includes twisted pair, unshielded twisted pair (UTP), shielded twisted pair (STP), coaxial cable, fiber optic cable, and wireless communication

Twisted-Pair Cable

• Used for telephone and modern Ethernet networks.

Unshielded Twisted Pair (UTP)

• Contains pairs of wires with each of the eight copper wires covered by an insulating material

Shielded Twisted Pair (STP)

• Uses shielding, cancellation, and wire twisting with each wire pair wrapped in metallic foil, and an overall metallic braid/foil around the four pairs

Coaxial Cable

• Used for video, communications, and audio transmissions
• Enables broadband cable Internet connection using a cable modem.

Fiber Optic Cable

• Contains optical fibers (usually glass) coated in plastic.
• It sends data by pulses of light
• Single-mode fiber: allows one mode of light to propagate; capable of higher bandwidth and greater distances, often used for campus backbones
• Multimode fiber: allows multiple modes of light to propagate; used for workgroup/intrabuilding applications using LEDs
• 2 km is the maximum cable length

Wireless Communication

• Uses radio frequencies (RF) or infared (IR) waves to transmit data
• Wireless LANs use a wireless hub, or access point, for signal distribution

Networking Devices and Testing Device

• Different networking devices have different roles in a computer network, working in different segments.
• Hubs enable network communication, using Ethernet cables but cannot identify the source or destination, sending information to all connected computers simultaneously but can only send or receive information at a time
• Switches work similarly to hubs but identify the destination to send information only to the intended computers and they can send and receive at the same time making them faster than hubs
• Bridge: a networking device that connects the other bridge networks which use the same protocol, and it connects two local-area networks.
• Router enables communication between networks and can pass information between two networks
• Wireless Access Points (AP or WAP): provides wireless access to a wired Ethernet network by way of plugging into a hub, switch or wire router
• Patch Panel allows connecting/managing multiple devices in computer networks, sound studios, and television stations.
• Modular Box (Network): It serves as a surface-mounted connector for network cables in commercial and industrial environments.
• Repeater regenerates or replicates a signal, used in transmission systems to regenerate analog or digital signals distorted by transmission loss
• RJ-45 Short for Registered Jack-45 and is an 8-pin connection used for Ethernet network adapters

Network Cable Tester

• Used to test the integrity and connectivity of cables.

Punch Down Tool

• A hand tool that is used to connect telecommunications and network wires to a patch panel, punch down block, keystone module, or surface mount box.

Crimping Tool

• A device used to conjoin two pieces of metal by deforming one/bot in a way that causes them to hold each other.

Wire Stripper

• A tool for removing the protective jacket (covering) from a cable to access inner wires.