Finally, the time has come for me to learn the most important network model on Earth! This is known as the TCP/IP model and it's essential for a tech to know. (Once again) Today, I will summarize my lessons on this blog. Also it's important to remember that a lot of basic info was already covered in the previous blogs on the OSI Seven Layer Model, since the TCP/IP model is not very different, just way more efficient.
Let's begin by giving some background info and stating the layers of TCP/IP. So, back in the day the OSI Model was made to universally connect the different protocols from different manufacturers. In today's world the OSI Seven Layer model is not important but it is something that many techs know to understand the basics of networks. The most important network model is TCP/IP for sure! To have that old system in a world of single protocol suites is illogical, so that's why the TCP/IP system is so essential in our world and why we must know it. Now, the layers are as follows: Link/Network Interface, Internet, Transport, and Application. There is not much standardization in the system, which makes it great for varietal purposes. To give a good example the Link Layer is also widely known as the Network Interface Layer. This brings me to the first layer.
The first layer is known as the "Link Layer" and the "Network Interface". What this layer essentially does is combine Layer 1 & 2 of the OSI model into one layer. There's not much to say for this layer, or some of the others (especially according to my textbook) but I will try to explain good ways of distinguishing the different layers. To seperate some layers think of the packets and frames. The part of the network that deals with frames is the Link Layer. When the IP packet is opened then you move on to the Internet Layer.
The second layer is the "Internet Layer". To really summarize this, the Internet layer focuses mainly on IP packets. Anything that deals with IP packets is a part of the Internet layer. IP addressing and the delivering of the packets are all in itself also a part of the Internet Layer. That's all there is to say really (if you want more in-depth information of some layers, I cite the earlier posts in my blog.)
The third layer is the "Transport Layer" which combines some parts of the OSI Transport Layer, the OSI Session Layer, and even the Application layer (on the OSI model)! The TCP/IP model is very busy working with assembling and disassembling data, but it defines other functions that may be connection or connection-less communications. The POP (Post Office Protocol) is used for sending and verifying e-mails and messaging. It's great because it makes sure that the message is not corrupt! In addition there are other TCP/IP protocols used for VoIP (Voice-Over IP). This brings me to a very important aspect of this layer, TCP and UDP. The TCP (Transmission Control Protocol) is connection-oriented, while UDP (User Datagram Protocol) is not. And that's where I will end it for now! Keep checking the blog, new entries daily. Bis bald.
I would not say that the TCP/IP model is "more efficient". It is just that TCP/IP is the actually implemented network protocol stack in use, while the OSI model is a theoretical model. You can see from your diagram that they map well together, with the four layers of the TCP/IP stack lining up with one or more layers of the OSI model.
ReplyDeleteWhat will be important for you to understand are the reasons for a layered architecture in the first place. Check out http://blueadmiral.com/Communications/comms/keyben.shtml for a nice summary I came across by Googling "advantages of a layered network architecture". I know the reasons for a layered architecture are part of the CISCO curriculum, and they probably are part of the Net+ curriculum as well (I'll check with our Networking teacher). In any case, it would be well worth your time to give it some serious consideration.
I read it, and see that it does have it's usefulness. It seems to be most useful to, as it said, the Telecom and Datacom Industry. The summary mainly stressed the independence of each respective layer. To be honest, I simply assumed that TCP/IP was more efficient since it's widely used, and it combines some of the layers of the OSI model and its tasks.
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