OSI Model

Layer 1 Physical

This layer encapsulates the physical aspects of a network, describing the physical signals that are sent through the cables and fibers on the network.

• EX: Cabling, punch-downs, ect.

Layer 2 Data Link Layer

The network “language” the foundation of communication at this layer. Also known as the Mac Address layer because this layer is associated with the Network cards & these are usually ethernet adapters or wireless adapters. We refer to the physical address on that device as the MAC address also known as switching layer

Layer 3 Network layer

This is the layer that routers us the forward traffic. IP addresses are used to treasure the network. Fragment Frames traverse different networks.

Layer 4 Transport Layer

Also known as the “Post Office” layer

• The ability to transport info from 1 device.

• Protocols used at this layer are TCP & UDP

Layer 5 Session Layer

Provides Communication Management from point A to point B. Starting, stopping, restarting sessions
- Control Protocols & tunneling.

Layer 6 Presentations Layer

Puts all the data into a format we can see. Character encoding, application encryption is often combined w/ application layer

Layer 7 Application Layer

The layer we see on our screen HTTPS, FTP, DNS, POP3 application protocols