[Computer Network] Protocol Architecture

Last Class

• computer networks -> Digital Network
• internet
• ip address
• data packet
• AP (memory + CPU)

WAN: Wide Area Network

• SK Telecom
• LGU+
• KT

1. WAN node 에서 packet 이 AP 로 들어온다.
   packet은 [source address | destination address | data] 로 구성된다.
2. AP에서는 CPU가 packet을 처리하고 메모리에 저장된다.
3. sub network들은 각자 ip주소와 port 가 있다.
4. need to decide where to go (what port) - Routing
5. [port | ip] address is located in memory (like table) -> Routing Table
6. final action: forwarding packet to port 

[Summary - main idea of Computer Networks (packet-switching based networks) ]

• Store
• Routing
• Forwarding

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• Interent
• Packet Switching Network
• Store and forward

Store and forward - Wikipedia

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Layered - Architecture

System (computer device) has some communication architecture
-> Layered Architecture

like Package delivery system

• internet ip address (internet protocol)
• ip protocol support end-to-end delivery
• end means end node
• to exchange data with end to end we need address so use ip address

Physical (real) delivery system

• in physical delivery system, we may have road, hub, terminal, your apartment(mom dad you), 
• path: consist of a set of link(edge)
• path actually means end to end delivery
• above picture has 4 links
• end to end delivery consist of hop to hop delivery
• one thing that we do not cover in this delivery system to get the package successfully

Hop-by-hop transport - Wikipedia

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Process to Process delivery (like Tom to John)

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정리

packetSwitching 기본 테크닉

• store
• routing
• forwarding

시스템 이해하려면 아키텍처를 이해해야함 (계층적 구조)

• (윗단) process to process 간에 통신을 하려면 패킷이 시스템에 와야한다.
• (중간) end to end delivery 시스템까지 도달하는 방식
• (아래) hop to hop delivery : path 가 되려면 여러개의 Link 로 구성되어 있으니 Link 단위로 넘어가는 것

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