Layers Of The OSI Model

From https://www.geeksforgeeks.org/layers-of-osi-model/

What is the OSI Model?

• The Open Systems Interconnection Model (OSI Model) was developed by the International Organization for Standardization (ISO) in 1984.

• There are seven layers to this model.

  1. Physical Layer - actual physical connection between devices (wires, connectors, etc)

  2. Data Link Layer - data transfer from node to node

  3. Network Layer -

  4. Transport Layer -

  5. Session Layer -

  6. Presentation Layer -

  7. Application Layer -

• Data has pieces added on to it as it goes from Layer 7 to Layer 1 in a process called encapsulation and pieces taken off it as it goes from Layer 1 to Layer 7 in a process called deencapsulation

Physical Layer

• Information is transmitted in binary in bits

• Wires, Connectors, Hubs, etc are what this Layer consist of

  • Topologies (bus, star, mesh, ring)

  • Transmission modes (simplex, half-duplex, full-duplex)

• A Layer 1 issue refers to a faulty connection, or crosstalk or interference on wires, or something of this nature.

Data Link Layer

Network Layer

Transport Layer

Session Layer

Presentation Layer

Application Layer