api: YAML JSON TOON Database
version: 1.0.0
format: json
dataset:
  slug: osi-model-layers
  title: OSI Model Layers
  description: The seven layers of the OSI reference model.
  summary: The seven layers of the OSI reference model, numbered from the physical layer (1) up to the application layer (7), each with its function and example protocols. It is the shared vocabulary for saying where in the stack a device, protocol or fault belongs.
  use_when:
    - You need the numbering and names of the layers, for example to explain what a 'layer 7 firewall' or 'layer 2 switch' does.
    - You are teaching or troubleshooting by working up or down the stack.
  caveats:
    - OSI is a reference model. TCP/IP, which the internet runs on, groups the upper three OSI layers into one application layer.
    - Many protocols do not sit cleanly in one layer; TLS, for example, is placed at layer 6 or 5 depending on who is drawing it.
  related:
    - tcp-ip-protocol-suite
    - network-topologies
    - network-security-devices
  category: Networking
  category_slug: networking
  tags: networking,osi,protocols
  view_count: 0
  entry_count: 7
  fields:
    - section: data
      field: layer
      type: integer
      example: "7"
    - section: data
      field: name
      type: string
      example: Application
    - section: data
      field: function
      type: string
      example: Network services for applications
    - section: data
      field: example_protocols
      type: string
      example: HTTP, FTP, SMTP, DNS
data:
  - layer: 7
    name: Application
    function: Network services for applications
    example_protocols: HTTP, FTP, SMTP, DNS
  - layer: 6
    name: Presentation
    function: Data translation, encryption, compression
    example_protocols: SSL/TLS, JPEG, ASCII
  - layer: 5
    name: Session
    function: Manages sessions between applications
    example_protocols: NetBIOS, RPC
  - layer: 4
    name: Transport
    function: End-to-end communication and reliability
    example_protocols: TCP, UDP
  - layer: 3
    name: Network
    function: Logical addressing and routing
    example_protocols: IP, ICMP, OSPF
  - layer: 2
    name: Data Link
    function: Node-to-node framing and media access
    example_protocols: Ethernet, PPP
  - layer: 1
    name: Physical
    function: Raw bit transmission over media
    example_protocols: USB, Ethernet cables, radio