学习笔记：高级信息网络Ch1.Evolution

(来源：notes of course Advanced IT Network. Ch1.Evolution)

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（非常没意思的一章，历史向。）

Analog:

• information is reprented by continuous variables.

Digital:

• discrete variables.

Full mesh network:

Central switched network:

To transfer code to message:

ASC2 –> Unicode

ISDN(Intergrated Service Digital Network):

• widely used for telephony
• marginal for data applications

LAN:

WAN-LAN intergration:

Three tier architectures:

• 通俗说，就是把服务器封装起来，用户和中间层交互

（其他的内容太无聊了，不写了。。。）