The 7 layers of “Networking” well kind of, the OSI model standardizes how data is transmitted over the network from what you see on your screen to your data being broken down into 1s and 0s that is send over type of network media such as cable, fiber or wireless. There is also another model that is called the TCP/IP which I’ll compare with another post.

Data is broken down from Data to Segments to Packets to Frames to Bits. The way I was told to remember the order the way the data is broken down is “Don’t Send Pete For Beer” from one of my college professors and I’ve yet to forget it. Similar with the 7 layers of the OSI model All People Should Take New Data Processing which is a bit dated now of days.

Application Layer – Closest layer to the user, where the user interacts with the applications that provide network services such as your email client or your web browser. Protocols that you would see at this layer would be HTTP, DNS and SMTP.

Presentation Layer – Data Encryption occurs at this layer and makes sure that the data is in a usable format. The protocols at this layer are SSL/TLS JPEG.

Sessions Layer – Maintains the connection between devices by establishing, managing and terminating sessions between devices. Protocols are this layer would be SIP, RPC.

Transport Layer – Transmits data using transmission protocols such as TCP or UDP. Data is broken down into segments.

Network Layer – Routing of data occurs at this layer as well as IP addresses, Routers at the device that are at this layer. Protocols include IP, OSPF, EIGRP. ICMP. Data is broken down into Packets

Data Link Layer – Device to device transmission occurs at this layer within the same network, Physical addressing such as MAC addresses. Switches and NICs are the devices at this layer. Protocols are APR and Ethernet, Data is broken down into Frames.

Physical Layer – Is the physical connection between devices such as cables and connections. Data is broken up into bits; Hubs are the hardware at this layer. Ethernet Cat, Fiber, radio waves happen at this layer. Protocols are Physical Ethernet and USB.