When two people are able to communicate we generally assume that they know the same language, and that is the key to understanding each other. This applies to the world of computing as well, where the set of standards are called protocols. During this article we plan to present in a nutshell the most common TCP/IP protocol types. We wonít get in-depth, so donít expect university course-style materialójust the basics.
Before we move on, let's fully grasp the concept of protocol and explain how more of those build up a structure called the OSI model. How are they important to us? Finally, we'll get into enumerating the popular TCP/IP protocols. These are the ones we need to be familiar with, since our applications and Internet surfing happens through them.
As mentioned earlier, in the simplest terms, a protocol is a set of rules and conventions that characterize some communication type. It defines specific elements like syntax, semantics, etc. It's the way that speaking and writing leads to understanding. If we were to throw together letters and words without any reason or order, no one would understand us.
TCP/IP is a suite of two protocol collections, TCP (Transmission Control Protocol) and IP (Internet Protocol). And that is why the TCP/IP is the most important protocol we can talk about when it comes to Internet-based communications. It is a prerequisite of the Internet. In a future article we will cover routing protocols (with the help of which routers work), VoIP protocols (telephones), and cellular phone protocols as well.
You may have already heard of the OSI Model or perhaps the TCP/IP Model. These two conceptually define and gather protocols of communications into layers. There are distinct differences between those two, but let's keep things simple. First, the OSI model has 7 layers, because it distinguishes the three top layers which are encapsulated together in the TCP/IP model. Aside from these, they're "mostly" akin.
We won't mess with the lower-layer protocols (such as physical and data link layers) because, from the perspective of the user, it does not matter what happens "inside" the little black box; the end result is what truly makes a difference. On the next pages we will become familiar with the most common and important protocols from the Internet/Network Layer (IP-v4, v6; IPSec), Transport Layer (TCP and UDP), and lots of application-specific protocols like HTTP, FTP, SMTP, POP3, IMAP, etc.
Now that we know the underlying foundation of protocol types, we can move on.