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It is evident from this that networking devices can be designed up to a certain layer
of the Internet model, where they play an auxiliary role in data connection.

12.4 Network Access Layer

This layer defines the physical methods of communication within the local network
(such as through cables or wireless signals). Devices communicate directly with each
other without the need for redirection. One of the most well-known protocols
operating in this layer is the Ethernet protocol, which enables high-speed local device
connections, reaching up to 1 gigabit per second. Switch devices operate in this layer,
primarily assisting in building local networks.

12.5 Steps of Transmitting Data

The steps of sending data from one device to another in a network are similar to
sending a letter through postal mail:
• After writing the letter, it is placed in an envelope, and the sender's and

recipient's names and addresses are written on it.
• The letter is then stamped, and handed over to the local post office, which, in

turn, collects the letters and sends them to the distribution center in the main
area.
• The distribution center directs the letters to other distribution centers based on
the recipient's location until they are received.
Similarly, in computer networks, to send data from one end to another, the data is
divided into a series of packets, and these packets are sent sequentially through the
network.

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