Data Networking: Physical vs. Protocol

Now that you have learned a little about myself from my about me post, let’s dive into our first topic in my on-going series as a student of IT (that’s also my twitter handle btw @StudentOf_IT).

Physical and Protocol Networking

I believe students often forget with networking the physical medium, and the protocol used to transport the data are independent from each other. For example, my education curriculum or program focuses mostly on Transmission Control Protocol (TCP) Internet Protocol (IP) over Ethernet. Although, there is a relationship between the two, and both a physical medium and protocol are required to transport any data, IP is not reliant on Ethernet, and Ethernet is not reliant on IP.

Rules of the Road (or Network)

Confused yet? I was when I was trying to understand this. Picture the physical medium as a road. By itself, this road is meaningless, and dangerous without rules and control protocols. There is a clear path from one place to another, but the cars are driving at various speeds, sides of the road, and have little care for the cars around them. This is because a road by itself does not have rules. Have you ever been behind a group of people walking really slow taking up an entire hallway? This is because that hallway by itself has no rules. The people walking in the hallway make the rules or follow an established protocol.

Let us add the type of physical network cable into the equation now. For this example, we are going to use 1Gb Ethernet (e.g. 1GbE), however this applies to any type of optical or electrical cable (not to mention wireless). Ethernet is our rules on the road or physical medium. We have a speed limit of 1Gb (one billion bits per second), we must drive in given direction on a certain side (transmit or receive path) of the road, and any vehicle on the road must meet certain standards (Ethernet frame).

The next logical assumption is the protocol are the vehicles on the road right? Well half right, and this was the part I had the most trouble understanding. The vehicle itself is irrelevant. The cargo inside determines the protocol used. The protocol is providing you directions to how to reach your destination, and standards of how to handle the cargo.

Bring IT (The Network) Together

Let us put the two together now. The cargo will be using IP protocol, and the road will be Ethernet. You bought a shirt at Target that is too small for you. Because of this you want to return the shirt, and buy a new one. The shirt in this case is your cargo/IP packet (remember, this applies to any type of protocol). The shirt has determined you are going to Target, and because of the road (any physical medium), and the rules put in place on the road (ethernet) we know how to get there safely.

What if you do not have any cargo/requesting data?

This would be handled in the same way as the above example. The car might be empty now, but we were told how to handle the future cargo, and are already following the standards of how to transport it.

Wrap up

IP is not solely reliant on Ethernet, and Ethernet is not solely reliant on IP. In other words the road is not reliant on only one set of rules, and the rules can apply to more than one kind of road. If IP was implemented on a Fiber Channel network (as it was in the past), the road itself would be changed, but the rules would stay the same, like going from a paved to a gravel road. The rules on the road can be changed as well. Fiber Channel over Ethernet (FCoE) can be implemented on an Ethernet network instead of IP. This would change how we drive on the road. Britain driving on the left side of a paved road, instead of the right.

That is enough from me for now, check back soon to read my continuing series of experiences as a student of IT. 😛

Cory Peden – Student of IT

@StudentOf_IT

www.studentofit.com

 

About Me

Let us start with the basics. My name is Cory Peden, I am in school full-time at Century College pursuing an AAS degree in Information and Telecommunication Technology (ITT). After this semester I will be one class away from graduation. While going to school I work part-time in the food service industry, and am an intern with Greg Schulz at StorageIO.

IT was not my first career choice, or  second. When I first went to college back in 2007 I wanted to become a photographer, and travel around the world taking pictures of nature or architecture. After a year and a half of bad choices I was suspended. Lost not knowing what I wanted to do with my life I took a year and a half off. During this time I had become a certified trainer at work, and found I liked teaching people new things. This lead me to pursue a degree in education.

This lasted for about a year when I saw the direction education was taking, and all the red tape that goes behind being a  teacher. I did not want to go into a field that measured your success based on one standardized test, and not take into account conditions of the schools, or special needs some students might have. I also believe the whole education system needs a revamp, but that is a topic for another time.

Giving up on school, I tried my hand at management, but because of events happening in my personal life, I could not take the pressure, and was not mature enough for that much responsibility.

Everything turned around when one of my friends, who is an IT professional, showed me blade servers he was working on. He explained the concept of visualization to me, and how you could run multiple things on one single machine. This sparked my interest, and I started asking him questions. After a couple of hours of this he finally told me that I should enroll in Century’s IT program.

Two years later, I am now on track to graduate by the end of the summer term. Last semester, I was on the Dean’s list, I plan to take my CCNA certification test within 3 months of graduating. My end goal is to become a consultant, and/or run my own datacenter.

Looking forward to creating conversation.

Till next time

Cory Peden

BTW follow me on Twitter @Studentof_IT to be updated on the newest blog posts