Data Communication: Network Topologies, Transmission Media, and Network Models

Comprehensive practice flashcards covering network topologies, transmission media characteristics, network architectures, and the OSI and TCP/IP layered networking models.

Network Topology

The arrangement or structure of devices and connections within a computer network, describing how devices are connected and how data travels between them.

Physical Topology

The actual physical layout and arrangement of network devices, cables, and connections.

Logical Topology

The path and manner in which data moves between devices across a network, regardless of their physical arrangement.

Star Topology

A network topology in which every end device connects directly to a central device, such as a switch or hub, through which all communication passes.

Bus Topology

A network topology connecting multiple devices to a single shared main communication cable known as the backbone.

Terminator

A component installed at both physical ends of a bus topology backbone cable to absorb signals and prevent reflections.

Ring Topology

A network topology where each device connects to exactly two neighboring devices, forming a closed loop for unidirectional or bidirectional data flow.

Full Mesh Topology

A network design where every single device has a dedicated point-to-point connection to every other device, requiring $L = \frac{n(n-1)}{2}$ links for $n$ devices.

Partial Mesh Topology

A mesh network variation where only selected devices have multiple direct connections to others, while remaining devices maintain fewer connections.

Tree Topology

A hierarchical network structure that combines multiple star networks through core, distribution, and access layers.

Hybrid Topology

A network architecture that integrates two or more different standard network topologies (such as star, bus, or ring) into a unified network.

Point-to-Point Topology

A dedicated communication circuit linking exactly two devices or network endpoints directly together.

Transmission Media

The physical path or transmission channel through which data signals travel between a sender and a receiver.

Guided Media

Cabled communication media that direct data signals along a physical pathway, including twisted-pair, coaxial, and fiber-optic cables.

Unguided Media

Wireless communication channels through which electromagnetic signals propagate freely through air or vacuum without a solid conductor.

Unshielded Twisted Pair (UTP)

A flexible, cost-effective twisted-pair copper cable lacking an overall metallic shield, widely used in modern local area networks.

Shielded Twisted Pair (STP)

Twisted-pair copper cabling built with additional metallic foil or braiding to mitigate the effects of external electromagnetic interference.

8P8C (RJ45)

The 8-position, 8-contact modular connector standard universally used to terminate twisted-pair Ethernet cabling.

Coaxial Cable

A transmission cable featuring an internal copper conductor insulated by dielectric material, wrapped in a braided metallic shield and an outer jacket.

Fiber-Optic Cable

A high-bandwidth transmission medium that conveys data as pulses of light through a central glass or plastic core surrounded by reflective cladding.

Single-Mode Fiber (SMF)

An optical fiber characterized by an extremely narrow core carrying a single propagation mode of light, optimized for long-distance telecommunications.

Multimode Fiber (MMF)

An optical fiber featuring a broader core diameter that allows multiple propagation light modes, commonly used for shorter backbone runs within buildings and data centers.

Line-of-Sight (LOS) Microwave Communication

A terrestrial unguided communication link that uses high-frequency directional electromagnetic waves aimed directly between line-of-sight antenna towers.

Infrared Communication

A short-range, line-of-sight wireless transmission medium using light frequencies below visible light that cannot pass through solid walls.

Satellite Communication

A wireless transmission system that relays microwave-frequency radio signals between ground stations and orbiting artificial spacecraft.

Bandwidth

The maximum rate of data transfer across a given network communication path, commonly quantified in bits per second.

Client-Server Network

A centralized network architecture where dedicated server computers provide shared resources, data, and access control to requesting client workstations.

Peer-to-Peer (P2P) Network

A decentralized network design in which all interconnected computers have equivalent privileges and can act simultaneously as both clients and servers.

OSI Reference Model

A theoretical seven-layer conceptual framework developed by the ISO to describe, standardize, and analyze network communications.

Application Layer (OSI Layer 7)

The OSI layer closest to the user that interfaces with end-user software applications to deliver network services using protocols such as HTTP, DNS, and FTP.

Presentation Layer (OSI Layer 6)

The OSI layer responsible for formatting, translating, encrypting, and compressing data into a standard readable syntax for applications.

Session Layer (OSI Layer 5)

The OSI layer that coordinates communication dialogues by initiating, managing, and terminating communication sessions between applications.

Transport Layer (OSI Layer 4)

The OSI layer responsible for end-to-end communication, session reliability, segmentation, and flow control using protocols like TCP and UDP.

Network Layer (OSI Layer 3)

The OSI layer that performs logical addressing (such as IP addressing) and path determination (routing) across interconnected networks.

Data Link Layer (OSI Layer 2)

The OSI layer that organizes raw data into structured frames, manages physical MAC addressing, and oversees point-to-point node transfer on local network segments.

Physical Layer (OSI Layer 1)

The base OSI layer that handles the transmission and reception of unstructured raw bit streams over physical network media.

Transmission Control Protocol (TCP)

A connection-oriented transport protocol that ensures ordered, reliable delivery of data streams with built-in acknowledgment and error retransmission.

User Datagram Protocol (UDP)

A connectionless, lightweight transport protocol with minimal transmission overhead, chosen when speed and low latency take precedence over guaranteed delivery.

MAC Address

A unique hardware identifier assigned to a network interface controller (NIC) used for local data link communication within a network segment.

TCP/IP Model

A practical four-layer protocol suite governing internet operations, comprising the Application, Transport, Internet, and Network Access layers.

Data Encapsulation

The sender-side process of appending specific protocol headers and trailers to data as it passes downward through each consecutive network layer.

Data Decapsulation

The receiver-side process of parsing and stripping off layer-specific headers and trailers as incoming bit streams travel upward through the network stack.

Protocol Data Unit (PDU)

The specific discrete package format of data handled at any given network layer, including Data, Segments/Datagrams, Packets, Frames, and Bits.