---
# System prepended metadata

title: 第七堂
tags: [網路概論筆記]

---

---
title: 第七堂
tags: 網路概論筆記
---

### Peer - 2 - Peer

### Client - server
- server
    - always-on host ( 不會關機000 )
    - permantent IP address ( 永久固定 )
    - data centers for scaling ( 擴充容易 )
- clients
    - communicate with server
    - may be intermittently connected
    - may have dynamic IP addresses
    - do not communicate directly with each other

### Sockets
- API

## TCP services
- Connection-oriented Service
    - 連接導向
    - 三向交握
- Reliable data transfer service
    - 可信賴的傳輸
- Congestion-control service
    - 網路雍塞控制
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## UDP services
- Connectionless Service
    - 直接傳封包
- unreliable data transfer service
    - 不保證每個封包能抵達目標
- Does not include a congestion-control mechanism
    - 無網路雍塞控制
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