OSI Model and Data Transmission Concepts

The bottom layer of the OSI model responsible for the physical transmission of data. Determines cable types, connector specifications, and manages the electrical signals used for communication.

Provides a way for devices to access a network and send/receive messages. Focuses on physical addressing to identify devices and provides error-checking for reliable data transmission.

It handles logical addressing (IP addresses), enabling communication between devices across different networks. It also fragments data packets for transmission and reassembly at the destination.

The address used by the Network Layer to identify devices on the network. This is different from the MAC address used by the Data Link Layer.

A hardware component that allows a device to connect to a network. It handles communication between the device and the physical layer.

A device that acts as a central hub for connecting devices on a network. It forwards data packets intelligently based on destination MAC addresses.

A device that connects different networks, handling data routing between them. It is a key component in the Network Layer.

The process of dividing data packets into smaller pieces for transmission across a network. This is done to optimize for different network technologies.

The process of identifying and reporting network variations, such as packet loss or delays, to the original sender of the data. These diagnostics typically occur within networks, involving network devices like routers and switches.

A process where receiving systems check the integrity of data packets by comparing calculated values with those sent by the origin. Mismatches result in packet discarding.

This layer handles reliable end-to-end communication between devices, ensuring data integrity and proper delivery. Features include: application identification, data segmentation & reassembly, flow control, error detection, and session establishment.

The layer that manages the communication sessions between applications on different devices. It tracks data acknowledgments, synchronizes data flow, and establishes, manages, and terminates sessions.

This layer is responsible for formatting and translating data before it's sent across the network, ensuring the application at the receiving end can understand the message.

Content validation calculations are an exception to network layer diagnostics as they do not report variations back to the sending system. It simply discards the packet if the content validation fails.

The transport layer can offer connectionless, best-effort communication for applications that don't require guaranteed delivery. This means data packets might be lost or arrive out of order.

Some examples of functionalities provided by the Transport Layer are: application identification, segmentation of data into packets, flow control to prevent overloading, and error detection to ensure data integrity.

A standard that becomes widely accepted and used, even without formal approval or legislation.

A standard established by official legislation or regulation from a recognized body.

A global organization that develops and publishes international standards for a wide range of products, services, and systems.

An international organization focusing on telecommunications standards, particularly for network technologies.

A private, non-profit organization that develops and maintains consensus-based standards for the United States.

A professional organization that sets standards for a wide range of electrical, electronic, and computer engineering fields, including networking.

A trade organization that develops standards for the electronics industry, including telecommunications.

A network topology where all devices are connected to a single central cable (the bus). Data travels along the bus to reach its destination.

A network topology where computers are connected in a closed loop, like a ring. Data travels in one direction around the loop, passing through each device. It's easier to troubleshoot but a single break disrupts the whole network.

A network topology where all computers are connected to a central hub. Data from a device goes through the hub to reach other devices. It's easy to expand and troubleshoot but the hub is a single point of failure.

Easy to implement, requires less cable, doesn't use specialized network equipment.

Network disruption when adding/removing computers, break in the cable disrupts the whole network, difficult to troubleshoot.

Cable faults are easy to locate, making troubleshooting easier. Moderately easy to install.

Expansion can cause network disruption, a single break in the cable disrupts the entire network.

The range of frequencies a signal occupies, measured as the difference between the highest and lowest frequencies. It determines the channel's data-carrying capacity.

The number of bits transmitted per second, measured in bits per second (bps). It represents the speed of data transfer.

The physical distance a single bit occupies on the transmission medium. Calculated as the product of signal speed and bit duration.

Unwanted signals that mix with the original signal, causing distortion and corruption of data. Sources include electromagnetic interference, lightning, or switching.

Signal weakening as it travels through the medium, leading to loss of energy. This results in distorted signals at the receiver.

Signal leakage from one communication channel into another, interfering with data transfer. This can result from overlapping frequencies or poor cable shielding.

Reflection of the signal back towards the sender when the signal doesn't fully dissipate at the end of the transmission line.

Any imperfection in the communication medium, such as noise, attenuation, crosstalk, or echoes, that can cause signal distortion and data corruption.

A network topology that combines elements of two or more other topologies (like bus, star, or ring) to gain the advantages of each while minimizing their disadvantages.

Hybrid topologies offer benefits like improved reliability, scalability, flexibility, and cost-effectiveness through the combined strengths of the underlying topologies.

The complexity of hybrid topologies makes their initial design and infrastructure management more challenging.

The process of modifying an analog carrier signal (like a sine wave) to represent analog data. This modification can involve changes in amplitude, frequency, or phase.

A modulation technique where the amplitude of the carrier signal is varied to represent the analog data. Stronger data signals create higher peaks in the carrier amplitude.

A modulation technique where the frequency of the carrier signal is altered to represent the analog data. Higher frequency indicates stronger data signals.

A modulation technique where the phase of the carrier signal is shifted to represent the analog data. The amount of phase shift reflects the data's strength.

The process of converting digital data (1s and 0s) into an analog signal for transmission using techniques like Amplitude Shift Keying (ASK), Frequency Shift Keying (FSK), or Phase Shift Keying (PSK).