Computer Networks Intro

textbook

Computer Network

computer: SmartPhones, AP(Access, point), Printer, PC

• which means consists of CPU, Memory, Storage(optional)

Network: Similar to Graph(Vertex + Edge)

in network

• Vertex -> Node
• Edge -> link

Networks: A set of Networks 

example of networks

Two kinds of Link

• Wireless Network
• Wired Network (LAN)

Different types of networks: Heterogeneous network

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Computer Networks Example

example of Computer Network

This Subject will focus on Computer Networks

수업의 목표는 컴퓨터 네트워크

왜 하필 컴퓨터 -> 피씨나 노트북이 아니라 CPU와 메모리를 가진 Node를 컴퓨터라 한다.

이 디바이스가 연결된 네트워크를 공부하는 거라 컴퓨터 네트워크

네트워크의 정의는 노드와 링크

링크는 두가지 타입이 있는데 유선과 무선이 있다.

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Why Computer will bee used for the node?

each node use different data types -> all Data Types we want, are digital (0 or 1)

computer Network == digital networks

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you want to send some package to your friends
-> you need Address

address should be standard address -> IP (Internet protocol)

What is definition of the Internet?

need two important keywords to define

• IP: internet protocol (address)
• Heterogenous network: Different types or kind of network

example of heterogenous network

so

Internet: a set of heterogeneous networks based on IP (some textbooks use TCP/IP protocol)

but TCP is not mandatory so just IP

internet == computer networks == digital networks

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To Exchange data, data must be wrapped with packet

Packet Switching: 패킷교환

Packet Switching and Delays in Computer Network - GeeksforGeeks

Packet switching is a method of transferring the data to a network in form of packets. 
In order to transfer the file fast and efficient manner over the network and minimize 
the transmission latency, the data is broken into small pieces of variable length, 
called Packet. At the destination, all these small-parts (packets) has to be 
reassembled, belonging to the same file. A packet composes of payload and various 
control information. No pre-setup or reservation of resources is needed.

 

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How to deliver Data On the Internet?

this is this class main topic

computer network -> digital network -> IP address -> data wrapped by packet -> to wrap packet, need packet swiching tech 

All packets must have at least two important things to deliver data

1. sender address
2. receiver address

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정리

• 컴퓨터 네트워크를 알렴면 컴퓨터가 뭔지 알아야 한다
• 일상 생활속 컴퓨터가 아닌 CPU 와 메모리가 있는 기기 (연산하고 저장할 수 있는 기기)
• 패킷을 연산하고 저장할 수 있는 기기!
• packet switching 을 하기 위해서 CPU 와 메모리가 필요하다.
• 모든 노드는 CPU 와 메모리가 있다는 뜻이다.
• 센서 네트워크 또한 센서가 CPU와 메모리가 있다.
• 컴퓨터는 0과1을 따루기 때문에 결국 computer network == digital network
• 모두 교환되는 정보가 디지털이기 때문에 wireless , LAN, bluetooth 다 상관없고 상대방의 address와 디지털 형태의 패킷만 있음 된다.
• big network + ip = 인터넷