Networks rely on protocol to operate efficiently. Protocol is "an agreed upon format for transmitting data between two devices" (Webopedia, 2008). Network protocol design is explained by two models, The OSI model and the TCP/IP model.
The OSI model was developed by the International Organization for Standardization in an attempt to provide standards for how networks should work. The model is theoretical in nature, and is divided into seven different layers. Each of these layers defines certain features and functions of a network. It could be difficult to tell the difference between each layer, because some network systems do not completely follow the model. Still, the OSI model is considered to be "the model" to base all network protocols.
The 7 layers of the OSI model are, in ascending order, the physical layer, the data link layer, the network layer, the transport layer, the session layer, the presentation layer, and the application layer.
Now we will talk about what each of these layers is responsible for.
"The physical layer is the physical point of connection between a computer and the network. This layer controls the transmission of information, while specifying the mechanical and electrical characteristics of the protocol in terms of connector size, pin assignments, and voltage levels" (Raja, Nwankwo, & Martha, n.d.).
"The data link layer is primarily concerned with the packing and unpacking of data packets so that they can be encoded and decoded into bits that allow them to be sent through the network. This layer supports error handling in the physical layer. Also, this layer is sometimes divided into two sub-layers called the media access control (MAC) and logical link control (LLC). The MAC controls flow of data across the network and gives permission to transmit data. The LLC controls frame synchronization and flow control" (Raja,