(Christopher)Discuss the process of transforming a message, as it is received by the application layer, into a stream of signals transmitted by the physical layer.
The process of transforming a message into a stream of signals transmitted by the physical layer began at the application layer of the sending computer. Which deals with the level at which application programs interact with the network, by employing programming interfaces to request network services. The most commonly used application layer protocol is Hypertext Transfer Protocol (HTTP), which generates an HTTP packet. The HTTP packet is passed to the transport layer which uses a Transmission Control Protocol (TCP) to ensure that packets move over the network reliably and without errors, in addition to using the sender’s and receiver’s port addresses to link the application layer software to the network. After the packet is passed to the transport layer which surrounds it with a TCP segment, it is passed to the network layer which surrounds it with an IP frame that includes the IP address of the final destination. Then it is passed to the data link layer that surrounds it within an Ethernet frame which includes the Ethernet address of the receiver’s computer. Finally, the packet is passed to the physical layer, which converts it into electrical impulses for transmission through the physical cables to the router of the receiver (FitzGerald, 2021).
FitzGerald, J. D. (2021). Business Data Communications and Networking, Fourteenth Edition. Hoboken: Wiley.