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# System prepended metadata

title: LIFE Example

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# Life Example

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![](https://i.imgur.com/Ph4s9yN.png)


if Johnny want to buy the delicious coffee, how network help with Johnny.


## Overview 

Ok Now, he have to use transport layer to transport his packet, and this way he have two options.
One is TCP. another is UDP 


Versus
tcp -> reliable 
udp -> more fast 


port 443 -> https 
port 80 -> http

![](https://i.imgur.com/9xORk5n.png)



**Network layer**

deal with ip address and routers 


**Data link layer** 



We're deal with mac Address we're giving our switch direction to the next stop



![](https://i.imgur.com/cMHVsDv.png)
the ip address information inside a new layer 2 header and he change the source and destination mac address 


![](https://i.imgur.com/qCmu8Z4.png)


Quiz 1 

![](https://i.imgur.com/xTofZho.png)


Ans : a c e 

B and D is impossible
B: Because delivery should be layer 4 to deal with, ensuring -> TCP
D: logical and physical addressing -> probably is layer 2 
f: It is presentation layer 6



![](https://i.imgur.com/LuY6VIK.png)

Ok this problem is fucking easy, if you know 3-way handshake


Obviously, the answer is B