3.1.3 - Describe how communication over networks is broken down into different layers. Flashcards
What is the OSI model?
The OSI (Open Systems Interconnection) model is a conceptual framework that standardises the functions of network communication into seven layers, facilitating interoperability and understanding of network protocols and systems.
What are the seven layers of the OSI model?
7) Application
6) Presentation
5) Session
4) Transport
3) Network
2) Data Link
1) Physical
Describe the application layer of the OSI model.
The application layer provides interfaces for user applications to access network services. It includes protocols and services for tasks such as email, file transfer, remote login, and web browsing. This layer serves as the interface between the user and the network.
Describe the presentation layer of the OSI model.
The presentation layer is responsible for data representation, translation, encryption, and compression to ensure that data exchanged between applications is in a format that can be understood by both sender and receiver. It deals with issues such as data syntax, semantics, and encryption/decryption.
Describe the session layer of the OSI model.
The session layer establishes, manages, and terminates communication sessions between applications. It handles session setup, synchronisation, and teardown, as well as checkpointing and recovery mechanisms to support reliable data exchange.
Describe the transport layer of the OSI model.
The transport layer ensures end-to-end communication between devices across a network. It segments and reassembles data into manageable units, provides error detection and recovery, and ensures the reliable and orderly delivery of data between source and destination.
Describe the network layer of the OSI model.
The network layer is responsible for routing and forwarding data packets between different networks. It determines the optimal path for data transmission, handles addressing and logical network topology, and manages congestion control and packet sequencing.
Describe the data link layer of the OSI model.
The data link layer provides error detection and correction, as well as the means for data framing, flow control, and access to the physical medium. It ensures reliable point-to-point and point-to-multipoint communication over the physical layer.
Describe the physical layer of the OSI model.
This is the lowest layer of the OSI model. It deals with the physical connection between devices, including the transmission and reception of raw data bits over a physical medium such as cables or wireless signals.
