Transmission Media, OSI and TCP/IP stack

Transmission media is what is used to connect computers together and through which data is passed from computer to computer.

In a LAN there are two types methods of connecting the computers:

Cabling – either copper cable or fibre optic
Wireless

TCP/IP is based on a four-layer reference model. All protocols that belong to the TCP/IP protocol suite are located in the top three layers of this model.

As shown in the following illustration, each layer of the TCP/IP model corresponds to one or more layers of the seven-layer Open Systems Interconnection (OSI) reference model proposed by the International Standards Organization (ISO).