The OSI Model of Data Transmission in Cybersecurity and The First Two Layers

Data transmission is the physical transfer of data over a communication channel. A network model describes the layers of communication between devices, PCs, and items on a network delivering data. To keep everything on the same page when it comes to moving data, a model called the OSI model, or Open Systems Interconnection model if you ever want to use the full name, was made with seven layers to explain everything in data transmission. Here, I am going to be using this particular story to go over two of those layers and teach you all about this basic model for cybersecurity.

The first of these layers is the physical layer. This deals with physical devices like cables, modems, and physical dumb devices. The cables for this layer can include unshielded twisted pairs of cable pairs that are not covered and are susceptible to interference; shielded twisted pairs; fiber optic (cables that send light pulses instead of delivering electronic pulses down like in traditional cabling); and coaxial cables (a single thick conductor wire surrounded by a protective grounding shield).

The second layer is the datalink layer. It is about processing frames of data and deals with the media access control (MAC) address - the "address" of the network interface card - and the LLC (or logical link control ) to send data frames to their next locations. There are the ethernet interface cards, switches, and bridges as devices that operate on this particular layer. Multiple protocols run on this layer, including the ARP (address resolution protocol), the multiprotocol label switching protocol a.k.a MLSP, and the point-to-point protocol known as PPP. The ARP is used between two devices on a local area network in order to resolve IP and MAC addresses.