Networks and Network Devices: Communicating and Connecting

How Do You Interact with a Network

  • A network is a system of two or more devices linked by wires, cables, or telecommunications.
  • Networks enable sharing of hardware, software, data, and information.
  • Digital communications involve transferring data, instructions, and information between devices.
  • Key components: sending device, communications device, receiving device, transmission media.
  • Home networks allow multiple users to share internet, files, and hardware.
  • Business networks facilitate communication and resource sharing.
  • Intranet: internal network using Internet technologies.
  • Extranet: allows external access to specific parts of an intranet.
  • VPN: secures data transmission to an organization's network.
  • Wired networks: use cables, more secure, faster data transmission.
  • Wireless networks: use airwaves, less secure, more convenient.
  • Cellular networks: wireless communication networks (3G, 4G, 5G).
  • Communications software manages network connections and data transmission.

Network Structures

  • Networks are classified by topology, architecture, and geographic reach.
  • Topology: physical arrangement of devices.
  • Architecture: logical design of devices.
  • Geographic reach: network's span.
  • Common topologies: bus, mesh, ring, star.
  • Bus: all devices connect to a central cable; failure disrupts all devices.
  • Mesh: interconnected devices; failure of one device doesn't halt the network. Full mesh connects each device to every other; partial mesh may not connect all devices.
  • Ring: data travels sequentially; failure can halt network communication.
  • Star: devices connect to a central device; central device failure disrupts network.
  • Client/server network: servers provide resources to clients, managed by a network administrator.
  • Peer-to-peer (P2P) network: connects a small number of computers (under 10) directly; no administrator needed.
  • LAN: connects devices in a limited area.
  • WLAN: a LAN using wireless connections.
  • WAN: connects devices across a large geographic region.
  • MAN: operated by a city or county.
  • PAN: connects personal digital devices via Bluetooth.
  • BAN: personal network using implanted biosensors.

Network Standards and Protocols

  • Protocols define data format, coding, error handling, and data transfer sequence.
  • TCP/IP: common protocol suite; TCP routes data, IP provides unique addresses.
  • IPv4 and IPv6: types of IP addresses.
  • Standards for close-distance communication: Wi-Fi, LTE, Bluetooth, UWB, IrDA, RFIC, NFC.
  • Wi-Fi: wireless communication via radio waves, based on 802.11 standards.
  • 802.11 standards: a, b, g, n, ac, ax, with varying data transfer rates.
  • Bluetooth: short-range radio wave data transfer (up to 3 Mbps).
  • Bluetooth uses: connecting devices to car stereos, GPS, wireless photo transfer, replacing wired devices.

Network Connection Hardware

  • Nodes: devices on a network (computers, phones, printers, etc.).
  • Hubs: central point for network cables, transmit data to all devices.
  • Switches: central point, transmit data only to the intended recipient.
  • Routers: connect networks and direct information flow.
  • Modem: connects devices to a communications channel (e.g., Internet).
  • Digital modem (broadband modem): sends/receives data via digital line.
  • Types of digital modems: cable, DSL, ISDN.

How To: Set Up a Network

  • Home network setup: modem, router, wireless access point, devices.
  • Steps: purchase modem/router, enable wireless, configure network name and key, connect devices to the network.
  • Benefits of wireless printers: shared use, app-based printing.
  • Wireless printer setup: place within wireless range, access settings, connect to network, install printer app.
  • Improving wireless signal: extend antenna, use signal booster, centralize router location.

Secure IT: Secure a Network

  • Wireless networks are easily accessible, leading to risks.
  • Security measures: change default password, SSID name, encryption, MAC address.
  • Network risks: adware, spyware, viruses, worms, trojans, ransomware, rootkits.
  • Security tools: NAS devices, encryption, authentication, firewalls, biometric devices.
  • Network monitoring software: assesses network status, detects problems.
  • Packet sniffer software: monitors and logs packet traffic.
  • Detecting unauthorized access: check connected devices, secure network, enable firewall, use stealth mode.

Ethics and Issues: Responsibilities of a Network Professional

  • Network administrator role: plan, design, set up, secure, and maintain networks.
  • USENIX: nonprofit organization supporting network engineers.
  • Professional code guidelines: professionalism, social responsibility, personal integrity, privacy, laws, communication, system integrity, education, community responsibility, ethical responsibility.