Overview of Computer Networks and Data Transmission

Flashcards covering the fundamentals of computer networks, topologies, communication models (OSI and TCP/IP), and various network classifications based on the provided lecture notes.

Computer Network

A system consisting of standalone computers (network nodes) connected via physical media based on a specific network architecture and capable of exchanging information.

Physical Media

The connection media used to link nodes, classified into wired (twisted pair, fiber optic, coaxial) and wireless (infrared, microwave, satellite).

Network Architecture

The methodology for connecting devices and exchanging information within a network.

Topology

The geometric arrangement or physical layout of network nodes and how they connect to one another.

Protocol

A set of rules governing how network nodes exchange and communicate information.

Star Topology

A network layout where a central device coordinates all activities; the network remains functional if a node fails, but fails entirely if the central hub fails.

Bus Topology

A layout where all nodes are connected to a single cable terminated at both ends; it saves cable length but makes fault detection difficult.

Ring Topology

A closed-loop layout where signals travel in one direction; a single cable failure stops the entire network.

Mesh Topology

A structure where every computer is connected to every other computer; it is the typical structure of the Internet and used for critical systems.

Server

A computer that provides information and services (such as email, web, or file services) to end devices in a network.

Client

A computer that sends requests to a server to retrieve information, such as web pages or emails.

Peer-to-Peer (P2P)

A network design where a device can act as both a client and a server; it is simple to set up but lacks central administration and scalability.

Intermediary Network Devices

Devices like switches, wireless access points, routers, and firewalls that connect end devices and manage data flow through the network.

Fault Tolerance

A network characteristic that limits the impact of failures by providing multiple paths for data transmission.

Scalability

The ability of a network to expand quickly and easily to support new users and applications without degrading the performance for existing users.

Quality of Service ($QoS$)

A mechanism used to manage data flow and prioritize traffic (like Voice over IP) to ensure reliable delivery.

Confidentiality

A security goal ensuring that only designated recipients can read the transmitted data.

Integrity

A security goal ensuring that data is not altered during the transmission process.

Availability

A security goal ensuring timely and reliable access to data for authorized users.

Physical Topology Diagram

A visual map illustrating the physical location of intermediary devices and cable installations.

Logical Topology Diagram

A visual map illustrating the devices, ports, and addressing schemes of a network.

Point-to-Point Topology

A logic type where a physical channel is established between two specific nodes for exchange, often referred to as Store-and-Forward.

Broadcast Topology

A logic type (Point-to-Multipoint) where all nodes share the same physical transmission path and check the destination address of every message.

Message Encoding

The process of converting information into another acceptable form for transmission over a channel.

Flow Control

The process of managing the rate of data transmission to determine how much information can be sent and at what speed.

Unicast

A message delivery option where information is transmitted to a single end device.

Multicast

A message delivery option where information is transmitted to one or more specific end devices.

Broadcast (Delivery)

A message delivery option where information is transmitted to all end devices on the network.

$$ARPANET$$

The predecessor of the Internet, established by the U.S. Department of Defense in 1969.

$IXP$ (Internet Exchange Provider)

Also known as an Internet Exchange Point, this provider provides the backbone connection for the Internet.

$ISP$ (Internet Service Provider)

An entity that provides Internet connection solutions to organizations, units, or individuals.

$ICP$ (Internet Content Provider)

An entity that provides and updates information content such as economics, education, and sports on the Internet.

Converging Network

A network infrastructure capable of delivering data, voice, and video services over the same set of rules and standards.

$LAN$ (Local Area Network)

A network infrastructure spanning a small geographical area like a home, school, or office building, typically providing high-speed bandwidth.

$WAN$ (Wide Area Network)

A network infrastructure spanning a broad geographical area such as cities, countries, or continents, often managed by multiple service providers.

Intranet

A private collection of $LAN$s and $WAN$s internal to an organization, accessible only by authorized members.

Circuit Switching

A transmission technique that allocates a dedicated physical channel for a connection between two nodes for the duration of the communication.

Message Switching

A technique where independent messages containing source and destination addresses are stored and forwarded by intermediary devices.

Packet Switching

A technique where data is divided into small units called packets, which are routed independently and can share the same channel.

$PDU$ (Protocol Data Unit)

The data unit formatted at a specific layer, consisting of a Header (control information) and Payload (actual data).

Encapsulation

The process where a sending device adds layer-specific headers to data as it passes down the protocol stack.

$OSI$ Model

A 7-layer reference model (Physical, Data Link, Network, Transport, Session, Presentation, Application) for open system interconnection.

$TCP/IP$ Model

A 4-layer network model (Network Access, Internet, Transport, Application) used as the standard for the Internet.