How the OSI Model Works | Network Fundamentals Part 3

How the OSI Model Works | Network Fundamentals Part 3
The OSI Model Explained
Surely you've heard about the #OSI model. That's why you're here right?
Well, this is the right place for you! In this video we discuss models, and why they're used. We look into the physical, data link, network, transport, session, presentation, and application layers, and how they relate to the real world.
And finally, we look at an example. This shows how a web request flows through each of the layers.
For further study, I recommend:
CCENT/CCNA ICND1 100-105 Official Cert Guide
(affiliate) click.linksynergy.com/link?id...
networkdirection.net/OSI+Model
The answers to the quizzes in this video are found at:
networkdirection.net/Understa...
In part 4 we'll Look at how IP addresses work
Attribution
How to write address on the envelope correctly
• How to write address o...
The modern postage stamp
• The modern postage stamp
Disclaimer
This video contains affiliate links. I receive a small commission at no cost to you when you purchase using my link
#NetworkDirection
#CCNA
#CCENT

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[@NetworkDirection]

More to come!

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[@Vitalserum]

Love this, just backed you on Patreon - more than a fair deal! Thank you for compiling these. One thing; as a total newcomer, I was a bit confused about the mention of "layer 1" or "layer 2", even though this was specifically mentioned in the beginning. Would've been good to have these a bit more explained in this context.

[@itsjimbobgreen9467]

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[@Ali_Alhajji]

6:33 My answer is: The transport layer is responsible for the ports, which manage the flow of data going through the ports. If an application is using too much bandwidth, we can control its data flow in this layer without having to interrupt its process in the application layer.

[@NetworkDirection]

Well thought-out, well done. You might also be interested to have a brief look at a technology called 'Quality of Service' (just a brief look, it is quite complicated)

[@steve.T.]

@@NetworkDirection Thanks for the tidbit.

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keep up the good work I am watching these before networkfundamentals class begins

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[@aleksandragloba2783]

Thank you for making these videos! Explanations are much better than in my university course!

[@felleg4737]

My guesses on the 11:59 quiz: TCP/IP applications (Protocols): FTP(File Transfer Protocol), SMTP(Simple Mail Transfer Protocol), Telnet - Application layer; JPEG, MPEG, TIFF, GIF - Presentation layer; Service request, Session Control Protocol (SCP) - Session layer; Flow Control - Transport layer; Application layer: End-user services like web browsing and file transfer Transport layer: checks and fixes errors, then delivers data error-free Network layer: routers work at this level, and decide how and where traffic is forwarded along a path Physical layer: Hardware for sending/receiving data on a medium hope I didn't misunderstand something, if did please correct me.

[@TheBLACKWIDOW83]

Great work. Really enjoying these

[@shinimannan]

Thanks for such great explanation of the concepts. I thought these were very difficult to understand. But you have made them real simple and easy to follow.

[@NetworkDirection]

Good to hear!

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[@NetworkDirection]

Thanks! Just a few more days until the next one

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[@Jacob.Morningstar]

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[@NetworkDirection]

Glad to help

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thank you so much for making these videos :)

[@DiamondCrystal]

I always remember “All people seem to need data processing”

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Fantastic series! Thanks!

[@Jesamazin04]

Best understanding of encapsulation. This is one of the best videos.

[@NetworkDirection]

Thanks!

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[@NetworkDirection]

Thank you Jevster! We really appreciate your support!

[@gallerksee]

Man, this is very comprehensible! Thanks a lot so far!

[@NetworkDirection]

You're welcome

[@adnanhasan169]

thank you - helped me alot in this lecture - i will revise the video again for more better understanding. Great work.

[@0xg484]

I've already done CCNA1 but this is great to recap and I thoroughly enjoy your presentation style

[@NetworkDirection]

Awesome, thank you! I am glad you enjoyed it!

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Amazing lesson retainable and visual stimulating 😊

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This is the best way to teach. Great graphics and illustrations. Keep up the good work.

[@NetworkDirection]

Thank you so much for sharing this feedback!

[@AvantGrade]

Excellent, that's the example I was looking for ❤

[@NetworkDirection]

Glad to help!

[@alanspillane4231]

Great video and a great series. Currently studying electrical engineering and this topic is a new elective for us this year, so cheers for keeping me ahead of the game so far! Keep up the good content, will definitely be sharing with all other students.

[@NetworkDirection]

Thanks Alan, I had no idea networking topics were used in electrical engineering. What other network-ish topics do you need to cover?

[@cegceg2783]

Your videos are how I wish every other educational video would be.

[@NetworkDirection]

That's kind of you to say, thank y ou

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I really like the way that you simplify the information 👍🏼

[@NetworkDirection]

Thanks, that's one of my goals when making these

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[@EricMurdoch]

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When I found this video ,I knew I struck gold mine.

[@NetworkDirection]

Thanks! That's a nice comment to start my day with

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[@NetworkDirection]

Thanks

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[@NetworkDirection]

You're welcome!

[@ROGMINGAMING]

Respected sir this is Manoj from india. Your way of explanation and simplicity i never experienced in my college. With a huge respect my eyes are dropping tears of joy.

[@NetworkDirection]

That's a huge compliment, thank you!

[@patricksile]

Hi hope your are fine Sir, I enjoyed when youu send Analogy and mad a good one, it will stick better in my head, cause I had a better idea of the mailing than OSI. Thanks

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Thanks a lot for making these videos, I got to learn so much and I don't think I'll forget what I learned here.

[@NetworkDirection]

Thanks Jayashree, thats great to hear!

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Thanks Mr , nice information !

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amazing explaination . One of the best videos I have seen on this topic

[@NetworkDirection]

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These videos are so useful

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[@NetworkDirection]

Thank you!

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Thanks for sharing.

[@JJenny1111]

thank you! this really makes sense, and helps a lot

[@NetworkDirection]

Glad it was helpful!

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a lot of thanks to you buddy these are really in depth knowledge videos

[@NetworkDirection]

So nice of you

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Great videos! Thank you very much!

[@russwelch5827]

excellent explanation

[@TheRealStevenGlen]

These videos are great! Thanks

[@NetworkDirection]

Thanks!

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Thnx, as a computer sci major this pluses

[@sede189]

Awesome so far!

[@NetworkDirection]

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[@NetworkDirection]

Thank you!

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Wow. I love your videos. Better than any lecture at university...

[@NetworkDirection]

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Finally, someone is explaining networking and I am awake.

[@NetworkDirection]

Nice to hear it, thanks

[@alexramsey4618]

Excellent presentation. Thank you.

[@NetworkDirection]

Glad you enjoyed it!

[@thetech8961]

The intro got me!!!

[@JTuam101]

that intro LOL, best network tutorial in the history of youtube!!!!

[@NetworkDirection]

Soo good to hear, thansk

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im doing computer science degree specialized in network tech and cybersecurity and this series supported my revision for first sem networking exam last year.

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This video is pretty hard

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I came to these videos to get info on the basics for setting up a basic network for a quick job, and my brain is full of knowledge XD

[@aunmaqsood3129]

These tutorials are very insightful, thank you! I'm just kind of confused about how the layer 2 address of the frame doesn't change when it goes through the switch. Is it because the logical link between the two endpoints are created by the switch?

[@Jazzadrin]

This video really helped me solidify the OSI model into my memory. Please Do Not Throw Sausage Pizza Away!!!!!

[@NetworkDirection]

You'll never forget it now :)

[@kristiyanivanov7414]

Absolutely fun. Thanks.

[@NetworkDirection]

Glad you enjoyed it!

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[@imk8729]

Great videos, thanks.

[@NetworkDirection]

You're welcome!

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[@NetworkDirection]

Glad to help you on your journey

[@rglyneslava2514]

Thanks for this great video 😊

[@NetworkDirection]

You're welcome

[@rglyneslava2514]

Can I get the answer of the question ? I need it on my activity . Please🙏❣

[@rglyneslava2514]

Can I get the answer of the question ? I need it on my activity . Please🙏❣

[@michaelnolk9701]

love this!

[@NetworkDirection]

Thanks!

[@prakashmc2842]

Miga Arumai! Valthukkal!

[@NetworkDirection]

thanks

[@Ari-118]

Loved this video also 💖

[@trbgraphics5557]

Yeah this was an amazing series! How's your progress 2 years later? Just curious

[@Ari-118]

@@trbgraphics5557 well I didn't pursue it. Just wanted to explore some stuff, computer related of course. Right now learning Java in a bit detail. Android programming.

[@trbgraphics5557]

@@Ari-118 Oh that's awesome. So what do you do as a main career? or are you a studying still

[@Ari-118]

@@trbgraphics5557 no no, just a hobby.

[@NetworkDirection]

Thank you!

[@NetworkDirection]

Quiz answers here: networkdirection.net/labsandquizzes/quizzes/understandingosi/ The CCENT/CCNA study guide (affiliate): click.linksynergy.com/link?id=RL4E*8CmbSY&offerid=145238.2445867&type=2&murl=http%3A%2F%2Fwww.ciscopress.com%2Ftitle%2F9781587205804 networkdirection.net/OSI+Model networkdirection.net/Understanding+OSI

[@El_Mr_Misterioso]

Application is closer to the end user, Transport delivers data in an error free way, network decides how traffic is forwarded and physical is the hardware to actually send the data over a medium

[@KenSherman]

Looking at this makes you understand why there is a TCP/IP model.

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[@NetworkDirection]

Most iconic IT quote on TV

[@deshawnmitchell9585]

Wonderful work...but hoped the answers for the little quiz was right in the vid

[@NetworkDirection]

It would make the videos a bit too long. Some of these are quite long already

[@jonasmayer2588]

Phantastic content! Im happy to support you on Patreon :)

[@NetworkDirection]

Thank you!!!

[@joshshaigan9629]

way above my head in understanding the material here. I'd like to know why it takes these steps for data to get to the destination host, then I think I would understand the description better.

[@gabelul_]

these steps are required so that the data can be safely and correctly sent to the reciever

[@aniswlidi2012]

Hi. Thanks for the effort. I just had a comment regarding the answers for the questions on the suggested website. We are required to be a member of Network's Patreon at $2 or more. Not happy with that.

[@amberalam6555]

Sir, with deep respect I would like to tell you that they way you explain these things is just awesome. I would like to talk to you about it all. If you got little time please let me know. I will wait for your response. There are two outcomes : either you reply or you do not reply. I am really hopeful that you will take atleast a minute to talk to me. Waiting eagerly. Thanks for these videos.

[@NetworkDirection]

Hi Amber, While I can't promise much, you're welcome to contact me at [e-mail]

[@MrSwagger5468]

I am confused so the transport takes care of the transport using udp or tcp protocol. With the example of port 80 it knows it needs to go thru the webserver. It adds a header The network makes sure it know it route by adding an source and destination ip. Adds it as a header Together they make sure the data is send to the right location? The data link makes sure it is in the right lan segment adding another header and a trailer correcting errors? Because it may hop from router to router the mac adress can change but the ip stays the same

[@co1355-tejastiwari]

Have you heard about tls transport layer security or tls handshake can you tell is it in osi model's transport or its something entirely else pls explain ,good session although

[@NetworkDirection]

Yes, I've heard of TLS. It's critical for security. It's a much deeper topic. I have some videos on security if you'd like some of the basics

[@mypuppygurl]

I lOVE your videos but can't afford the answers :( That suxs but ty for the wonderful videos. I have subscribed :)

[@CreativeHomeTutorial]

yes it is use ful

[@DarkbaseTTV]

Answers to the quizzes are only available with a login? :(

[@NetworkDirection]

Thanks for pointing this out, this is now fixed

[@kevingichamba3963]

@@NetworkDirection its not yet

[@sujanmagar9795]

I wanted to learn everything from the basic to advance. Please suggest me some books to pass certified exams.

[@avantikak6480]

Thank you so much for all the classes Sir, they were really helpful. Just a doubt, does fragmentation of data into packets happen at the transport layer or network layer? The book I've read it from mentions Network layer, but you've mentioned transport layer in your video? Also, just related to the addresses Transport layer: Port number Network layer: IP addresses Data link layer: Mac adresses present in the NIC. Is this right Sir, I hope I've understood it correctly?

[@NetworkDirection]

It looks like you've understood it correctly. The data from the transport layer is broken into packets, if that's what you're referring to Packets are sometimes too big, and need to be fragmented into smaller packets. This happens at the network layer

[@avantikak6480]

@@NetworkDirection so first data at the segment layer is segmented into segments, and if according to MTU the packets made at the network layer are too big, they are further broken down and this is known as fragmentation. Am I right Sir? Another doubt that I had was that when we say that layer 2 adresses keep on changing, we mean that the MAC adresses keep on changing depending on whichever device is next, be it router or host. But layer 3 address remains the same, as in the IP address in the frame is only of the destination, whereas the layer 2 address keeps on changing. I hope I'm correct?😬 Also, in your video you asked us to match certain descriptions with the layers. The description was: Delivers data error free... I feel that there could be 2 answers to this, one the Transport Layer due to connection oriented protocol TCP, but also Data Link layer since it adds the trailer to the frame for error correction? Are there actually 2 answers to this, or am I going wrong in the concept here Sir?

[@avantikak6480]

@@NetworkDirection I really appreciate you replying to my previous doubt Sir, and if you dont mind me saying, you have a really good voice 😂👍🏻. Even when I'm reading my computer books, I tend to hear them in your accent 😂

[@NetworkDirection]

@@avantikak6480 You've pretty much got it. There are some exceptions to this, but you'll find those as you go along. You're right, layer 2 does have the trailer. Here's something to think about: Is TCP the only protocol operating at layer 4? It might help to watch a few more videos, then revisit this one.

[@NetworkDirection]

@@avantikak6480 Thanks! I don't hear too many people complimenting the Aussie accent

[@jiatuli6421]

Transport layer breaks down app data into segments/datagrams, but I am confused if network layer and data link layer function the same, like data link layer breaks down packets into many frames , so one packet consists of more than one frame? Thank you!

[@NetworkDirection]

Usually just the transport layer will do this. Sometimes a packet (layer 3) will need to be fragmented in to smaller packets, but we want to avoid this.

[@crockcode4971]

thanks but still not getting it right in my head but I will revisit this video various times to understand OSI layers..

[@NetworkDirection]

It can take revision. Just stick with it, you'll get there. Maybe look at some videos from other creators too. Some times we just need to hear a concept explained differently, and suddenly it all makes sense

[@user-lj9lb5rh5u]

what is the answer of the question number 1 about "which layer should be addressed"

[@huyang2885]

great

[@xeifora]

That intro... suddenly kill me, that's how we understand the humour in the IT universe XD

[@NetworkDirection]

Got to find some humour when we can :)

[@jiatuli6421]

Another question: Why the source MAC address of the second frame is not the same as the destination MAC address of the first frame?

[@NetworkDirection]

Routers update the source and destination MAC as frames pass through

[@StephenWoodburyofAagh]

How does the router know the mac address of the server? Does it request it from the server using its ip?

[@NetworkDirection]

That's a good question! This uses a process called ARP, which is discussed in a later video

[@lucamuller3207]

Any chance you work in the basement of an office building with a collegue named roy?

[@ericdreal1907]

bruh I feel personally attacked

[@ashikulislam377]

please some one tell me what is said in the quize1 ,, When a high bandwidth applications is causing to the network ' to slow down', then Transport layer is addressed. I can't understand this

[@77garga]

data needs to be segmented and thats done by TCP or UDP and they are layer 4

[@khari83637]

6:25 - I would guess layer 3 as it involves QoS and load balancing

[@lambpiefoon373]

Is this Hugo from DataCamp? Excellent Videos

[@NetworkDirection]

I've never heard of Hugo or DataCamp, but I'm glad you like the videos!

[@imbillionaire4741]

6:23 What is the answer?

[@williambjornstad]

@Killerelmo 4 fuck you bro