Whether it is the command prompt, the Internet, other various programs, etc. Without this level no service would be accessible. This means no GUI or graphical user interface (Capano,2014). In my opinion, I don't think you can take any layers off this model and the rest still works. All layers work hand in hand with the others. All data comes in through the physical layer, goes up to the application layer, and then comes down and out through the physical layer. All layers are crucial players in the OSI model. The TCP/IP model is the one currently used for IPv4. This is the current standard protocol for Internet addressing (Tetz, 2011). The network interface layer is responsible for managing the physical aspects of connectivity in a network. This, like the physical, network, and data link layer of the OSI model, has to do with converting data, establishing connectivity, sending data, and also maintaining the MAC address. The application layer in the TCP/IP model is similar to the OSI model. Two network hosts have a communication session, and the application layer is the endpoint at the two ends