OSI Reference Model - Best Explanation

The Open Systems Interconnection model (OSI model) is a conceptual model that characterizes and standardizes the communication functions of a telecommunication or computing system without regard to their underlying internal structure and technology. Its goal is the interoperability of diverse communication systems with standard protocols. The model partitions a communication system into abstraction layers. The original version of the model defined seven layers.

[lindsayshaver]

I want this dude to teach me everything he knows about network engineering.

[nick]

Dude... This guy has taught me more in a night than my Cisco networking I teacher has taught me in 2 months. Thank you so much!

[bharathmkulkarni]

These kind of professors make you fall in love with the subject !

[Jive-]

Nicholas Andre is the teachers name ha has a yt channel

[asdfasdf-ppjr]

_Drunk Engineer_ is not this lecturer's account.

Here is his actual account (and the rest of his videos) :

[samjackgreen]

00:50 WHY develop the OSI model?

05:02 The Application Layer

07:36 The Presentation Layer (Layer 6)

09:17 The SESSION Layer (Layer 5)

10:50 The Transport Layer (Layer 4)
11:00 TRANSPORT is not moving something from A to B.
11:20 It's responsibility is to get the SEGMENT to the right APPLICATION or SERVICE.
When I say APPLICATION you need to think "client".
When I say SERVICE, you need to think SERVER.
12:20 What port is the SERVER going to be listening on? PORT 80
Port 80 is the default port for web delivery.
13:25 It's not about picking up from A to B; it's about working out which service on the server needs the message (once the message has arrived on the server).
How does the server know to look for port 80?
Answer: the HEADER

16:10 Introducing RELIABLE DELIVERY
17:27 We gain EFFICIENCY
19:25 Does all communication need to be reliable?
21:58 FLOW CONTROL
22:24 Slap a header on there
In that header there are going to be "sequence numbers". We call them fields.
23:20 There's going to be a SOURCE port and a DESTINATION port.
25:47 What if I just throw it out there?
If you tried to verify every --item-- communicated, it would not be effective.
26:40 "I use unreliable delivery!"
27:27 UDP and un-reliable delivery
- If you don't get what I send, raise your hand!
- If I choose to use
28:20 "And that's what uTorrent does"
- To successfully download a file, you need all the bits
- But imagine if there was a check after each thing communicated!
- 29:00 Contrast with downloading a file on a web browser
- 29:26 Prime example of UDP delivery is VIDEO
31:30 As a DEVELOPER, you have to consider the trade-off between RELIABILITY and PERFORMANCE
31:49 Summary

32:00 NOTE on segmentation
- We may have multiple applications running concurrently.
- We'll probably have multiple computers on our network using our connection, concurrently.
- Segmentation isn't merely achieved by dispersing messages across several connections;
- It's also achieved by allowing multiple people to use each connection.

33:03 We multi-plex the conversation: we take segments from different conversations and interweave them together, so it looks like everyone's using the same network connection at the
same time.


33:27 The Network Layer (Layer 3)
34:24 By the time we get down to Layer 3, we have DEVICES
35:15 What is a packet?
36:00 Addressing mechanism
36:20 "The protocol used at Layer 3 is typically IPv4" - It could also be AppleTalk though.


39:53 The Data Link Layer (Layer 2)

41:10 The PHYSICAL Layer (Layer 1)
41:37 What is a frame?
42:15 The Logical layer and the MAC layer

[adeshkashyap]

Dont we have more videos from him ?? He is one of the best guy I have seen here, explaining everything in simple language ... Awesome ..

[hollowmanmaster]

Man - you are so awesome, I could listen you and learn every day and I think about everything what is related to Network, Computers !
Why only 2 videos .... I want more !
Great Job. Grats

[amitsky]

Best explanation so But the camera movement was bit annoying :)

[luvkashyap]

Some people are just born to be teachers !! You can see the passion with what he teaches, makes learning FUN, EASY, INTERESTING and biggest of all something you would remember for a long time

[flamingsantaable]

thanks for your video for the last cople days i was in to netacad stresing my out, i got few things out of there, but this video made everything more clearer. big thanks

[rushabhdudhe]

Did anyone feel bad at @21:45 for the guy who came late for the class...?

[VolatilityDoctor]

The name of your page brought me here,
However, Your advice made me stay.

[Fernandez]

i was complaining to my teacher in class about how abstract networking introduction is and i was having a hard time wrapping my head around the concepts. This guy is, perfect. He makes the abstract concrete. I wish I could give more than a like to this video.

[GPS]

Sir Kindly upload all the knowledge you have.
One of the best lecture ever heard.

[pandoraxd]

so i just became a master of osi model with just this? what was i doing wasting months in university lol. This guy is too gooooddd

[ibtesumrezaaninda]

Why this channel have only two videos??? Where can I find more videos of this guy?

[swapnilvmahajan]

I wish i met this guy exactly 10 years ago. This guy taught me more than Behrouz A. Forouzan and Tanenbaum.

[Fernandez]

youtube algorithm needs to make this guy's videos blow up. But I don't even know his name.

[TheSuperUser]

Awesome lecture and explained very well indeed