Introduction to Networks: OSI and TCP/IP

Vocabulary flashcards covering key terms from the lecture notes on networks, OSI/TCP-IP, topologies, media, and related concepts.

Network

A set of devices (nodes) connected by communication links that can send and receive data.

Node

Any device on a network capable of sending or receiving data (computer, printer, etc.).

Computer network

A collection of autonomous computers interconnected by a single technology, enabling information exchange.

Distributed system

A system where independent computers appear as a single coherent system to users, often implemented with middleware; example: World Wide Web.

Middleware

Software layer on top of the operating system that implements a distributed model.

World Wide Web

A distributed information system that runs on the Internet and presents information as documents (web pages).

OSI model

Open Systems Interconnection model; a seven-layer conceptual framework for network interactions to enable interoperability.

Physical layer (OSI)

Bottom OSI layer; transmits raw bits over a physical medium.

Data Link layer (OSI)

OSI layer responsible for node-to-node data transfer, framing, and error detection.

Network layer (OSI)

OSI layer responsible for routing and forwarding packets through the network.

Transport layer (OSI)

OSI layer providing end-to-end communication control and reliability.

Session layer (OSI)

OSI layer managing sessions between applications.

Presentation layer (OSI)

OSI layer handling data representation, encryption, and translation.

Application layer (OSI)

OSI layer providing network-based applications and services to end users.

TCP/IP model

Practical protocol suite with four layers: Application, Transport, Internet, Network Access.

Internet

Global network of networks that interconnects millions of devices; backbone of the Internet.

Local Area Network (LAN)

A network designed for a small geographic area (building, campus); typically uses Ethernet or WLAN.

Metropolitan Area Network (MAN)

Larger network spanning a city or campus; connects multiple LANs and may use fiber.

Wide Area Network (WAN)

The largest-scale network, spanning long distances and often connecting multiple LANs/MANs; e.g., Internet.

Campus Area Network (CAN)

A MAN for a campus; links buildings within a campus.

Ethernet

A LAN technology using CSMA/CD for medium access; standard for wired networks.

CSMA/CD

Carrier Sense Multiple Access with Collision Detect; Ethernet access method that listens before transmitting and detects collisions.

Token Ring

LAN access method using a circulating token to grant the right to transmit.

ArcNet

An older LAN technology.

100VG-AnyLAN

A LAN technology (older standard) for local area networks.

Open architecture

Concept of interoperable, vendor-neutral system design within networks.

Point-to-point

A dedicated link between two devices with exclusive use of the link capacity.

Multipoint

A shared link among three or more devices where capacity is shared.

Simplex

One-way data transmission.

Half-Duplex

Two-way communication, but not simultaneous.

Full-Duplex

Simultaneous two-way communication.

Physical topology

The physical layout of devices and links in a network.

Mesh topology

Topology where every node connects to every other node (full mesh vs partial).

Full mesh

Every computer in the network has a direct connection to every other computer.

Partial mesh

Some but not all pairs of computers are directly connected, providing redundancy.

Star topology

All devices connect to a central hub or switch.

Bus topology

All devices share a single backbone cable; data travels along the backbone.

Ring topology

Devices connected in a closed loop; data circulates around the ring.

Hybrid topology

Combination of two or more topologies (e.g., star with bus branches).

Bridge

Device that connects and forwards traffic between LAN segments.

Performance (network criterion)

How fast data moves in a network, including transit time and response time.

Throughput

Actual amount of data successfully transmitted per unit time.

Delay

Time data spends traveling through the network; affected by congestion.

Reliability

Frequency of failures, recovery time, and robustness of the network.

Security

Protection of data from unauthorized access and loss; includes recovery policies.

Transmission medium

Path that carries signals between devices; can be guided (wired) or unguided (wireless).

Guided transmission media

Wired media such as twisted-pair, coaxial, and fiber-optic cables.

Unguided transmission media

Wireless media such as radio waves, microwaves, and infrared.

Bits

The basic unit of data at the Physical layer.

Frames

Data units at the Data Link layer.

Packets

Data units at the Network layer.

Segments

Data units at the Transport layer.

Data

Application-layer information prepared for transmission.

ISDN

Integrated Services Digital Network; a digital network service for WANs.

SONET

Synchronous Optical Network; high-speed optical networking standard.

HDLC

High-Level Data Link Control; a data link layer protocol.

SDLC

Synchronous Data Link Control; an older data link protocol.