OSI Flashcards
What does OSI stand for?
Open Systems Interconnection
What is OSI
OSI is a model (conceptual framework) that standardizes the functions of a telecommunication or computing system into seven distinct layers, each with its own specific functions and responsibilities.
What is the purpose of the OSI model
The OSI model was developed by the International Organization for Standardization (ISO) to provide a standardized way of understanding and organizing the various components and protocols involved in network communication. It serves as a foundation for understanding how different networking protocols and technologies work together.
Why is understanding OSI useful?
Understanding the OSI model helps network engineers, developers, and other IT professionals conceptualize and troubleshoot network communication, design protocols, and develop network applications. Each layer has its specific functions and interacts with adjacent layers to facilitate efficient communication within a network.
Who is ISO?
The International Organization for Standardization (1947 | Geneva, Switzerland) is an independent, non-governmental international organization that develops and publishes voluntary international standards for a wide range of industries. The organization’s mission is to facilitate international trade and ensure the quality, safety, efficiency, interoperability, and consistency of products, services, and systems.
What are the layers of the OSI model?
Physical
Data Link
Network
Transport
Session
Presentation
Application
What is the Benefit of Standardization from ISO?
Benefit of Standardization: ISO standards provide several benefits, such as facilitating international trade, ensuring product quality and safety, enhancing efficiency, enabling interoperability, reducing costs, and supporting regulatory compliance.
Physical Layer (Layer 1 of 7)
The physical layer deals with the physical aspects of transmitting raw data over the network medium, such as cables, switches, and electrical/optical signaling. It defines specifications for hardware like cables, switches, and network interface cards.
Data Link Layer (Layer 2 of 7)
The data link layer focuses on the reliable transmission of data frames between devices on the same local network. It provides error detection and correction and controls access to the physical medium, often using protocols like Ethernet.
Network Layer (Layer 3 of 7)
The network layer is responsible for routing packets between different networks and subnets. It determines the best path for data packets to travel from the source to the destination using ‘routing’ algorithms.
IP (Internet Protocol) is a key protocol at this layer.
Transport Layer (Layer 4 of 7)
The transport layer manages end-to-end communication and ensures data integrity and reliability. It also deals with flow control and can fragment and reassemble data.
Protocols like TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) operate at this layer.
Session Layer (Layer 5 of 7)
The session layer establishes, manages, and terminates sessions or connections between applications. It provides services such as session establishment, maintenance, and termination, as well as synchronization between applications.
Presentation Layer (Layer 6 of 7)
The presentation layer is responsible for data formatting, encryption, decryption, and data compression. It ensures that data is presented in a readable format for the application layer and handles issues related to data representation and formatting.
Application Layer (Layer 7 of 7)
The application layer is the topmost layer and provides network services directly to end-user applications. It supports communication and data exchange between software applications.
Protocols like HTTP, SMTP, and FTP operate at this layer.
What is UDP?
User Datagram Protocol is a connection-less protocol, which means it doesn’t establish a connection before sending data. It transmits data in discrete units called datagrams. When there’s enough data to send, UDP immediately sends the datagram without waiting to accumulate a larger amount of data. However, this lack of a connection and the immediate transmission also mean that UDP does not guarantee delivery, ordering, or duplicate protection.
