Ham

Modem vs Gateway vs Router

Modem — process the signal from ISP and interfaces to the home network .

https://www.youtube.com/watch?v=Ea4rMYM_Mz8

Modem:

Not intlligent
Not programmed
Not data protection
Do not has a firewall

Router — create a local network with each device has uniq ip adds.

Intelligent device
Every digital router contains a modem
Router provides firewall func
Tunel options provides (IPsec, GRE , PPTP ,OpenVPN tunes options)
May include IO functionality.

Gateway — they provide protocol translation (zigbee, mudbus , celluar, PCI , RS-232 ….)

Less traffic control
Simple to configure
I/O options
Gateway is a protocol translator .

Switch — one port to many. But don’t assign different ip.

Network bridge — link devices together linear.

Network hub — dose not analyze traffic, just broadcast anything to every port .

Modem — Translates different form of data (analog to digital, digital to analog)

Gateway — Translates same data for different protocols

Router — includes a modem sometimes (wires to wifi for example)

RF modem

调制解调器（英语：Modem，modulator-demodulator的英文缩写）是一个将数字信号调变到模拟信号上进行传输，并解调收到的模拟信号以得到数字信号的电子设备

Модем (ағылш. modem, modulator-demodulator) — сандық сигналдарды аналогтық сигналдарға айналдыратын және керісінше амал жасайтын электрондық құрылғы.