In this chapter, we've taken a look at port numbers and their importance on a system. Without port numbers per services, a computer will have a challenge processing any messages it has received from a sender. For every port number, there's a service or network protocol that is mapped to it. Each network protocol handles the formatting and encoding of data in its own way and uses a unique port number for communicating with another device. So far, this chapter provided a better understanding in understanding and identifying network protocols and port numbers and understanding network design.
In the next chapter, we'll be covering Ethernet a bit more in-depth while providing the functions of its sub-layers and the fields within an Ethernet frame.