2.5 Networking Lecture Notes

A set of vocabulary flashcards covering networking hardware, connectivity devices, and security concepts as outlined in the lecture notes.

Modem

A device that uses $RJ11$ phone lines for dial-up internet by converting digital computer signals into analog telephone signals and back. It supports speeds up to $56\,Kbps$ and is rarely used today.

Cable Modem

An ISP device that connects a LAN to the internet using coaxial cable (F-type connector) and DOCSIS over cable TV infrastructure. It converts provider signals into Ethernet data and uses shared bandwidth.

DSL Modem (Digital Subscriber Line Modem)

A device that uses telephone lines ($RJ11$) to provide digital internet access.

ONT (Optical Network Terminal)

A device that connects fiber optics cables to other types of wiring such as Ethernet and phone lines by converting the signal from optical to electrical and vice versa. It is associated with FTTH (Fiber to the House).

WAP (Wireless Access Point)

A device that allows wireless devices to connect to a wired LAN using $802.11$ Wi-Fi standards.

Repeater / Extender

A physical device that boosts and extends network signals without modifying data, used to extend long cable runs or weak Wi-Fi coverage.

Hub

A legacy network device that broadcasts all traffic to every connected port without filtering. Used in outdated or test environments.

Patch Panel

A passive cable management device that organizes and connects network cables in a rack. It does not process or route data.

Switch

A device that uses MAC addresses to forward data only to the correct destination port to connect devices in networks.

Unmanaged Switch

A plug-and-play switch with little to no configuration options.

Managed Switch

A configurable switch that allows traffic control and monitoring features such as QoS, VLANs, port mirroring, and redundancy.

QoS (Quality of Service)

A feature that prioritizes important network traffic (example: VoIP calls) to improve performance and reduce delays.

Redundancy

The use of multiple network paths to prevent failures and improve reliability; it uses STP (Spanning Tree Protocol) to manage these paths.

Port Mirroring

A process that copies traffic from one port to another for monitoring and troubleshooting without interrupting the device.

Router

A device that connects different networks (LAN/WAN) and forwards data using IP addresses; provides DHCP, NAT, routing, gateway functions, and basic firewall protection.

Firewall

A security device or software that filters incoming and outgoing network traffic using rules to block unauthorized access and protect networks.

DMZ (Demilitarized Zone)

A separate network zone between the Internet and internal network that hosts public-facing services (like web, mail, DNS, or proxy servers) while protecting the private network.

ACL (Access Control List)

A set of firewall rules that allows or blocks traffic based on IP address, port number, domain name, or combinations of these.

Power over Ethernet Injector (PoE)

A device that provides power and data over one Ethernet cable to a single device like a WAP, camera, or VoIP phone.

PoE Switch

A device that provides power and data over Ethernet to multiple PoE devices while also connecting them to the network.