A modem is a device that converts a digital signal into an analog signal through modulation at the transmitting end, and converts the analog signal into a digital signal through demodulation at the receiving end. It has the function of modulation and mediation, and is the "translator" of analog and digital signals.
Electronic signals are divided into "analog signals" and "digital signals". Telephone lines transmit analog signals, and PCs transmit digital signals. Therefore, if you want to connect your computer to the Internet through a telephone line, you must rely on The optical cat modulates and mediates two different signals.
A switch (multi-port bridge, data storage and forwarding) is a network device used for electrical/optical signal forwarding. It can provide an exclusive electrical signal channel for any two network nodes connected to the switch. Switches can be divided into wide area network switches and local area network switches according to different working positions. Wide area network switches are devices that complete information exchange functions in communication systems, and are generally used in the data link layer. Each port of the switch has a bridging function, which can be connected to a local area network or a high-performance server or work.
A router (ie a gateway device) is an interconnection device that connects various LANs, WANs, and metropolitan area networks in the Internet. It is generally applied to the network layer. It will automatically select and set routes according to the signal conditions, and use the best path to follow the front and back. Send the signals sequentially. The router can be connected to multiple logically separated networks (a single network or a subnet), has the function of judging network addresses and selecting IP paths, and is the "traffic police" of the Internet.
When data is transmitted from one subnet to another, it is necessary to rely on routers to establish flexible connections, and connect various subnets with completely different data packets and cut-off access methods.
To put it simply, optical modems are equivalent to packaging factories, routers are equivalent to wholesale retailers, and switches are equivalent to logistics distributors. Generally, the analog signal transmitted by the network cable is converted into a digital signal by the optical modem, and then the signal is forwarded to the PC by the router. When the number of PCs exceeds the router connection, you need to add a switch to expand the interface.
The function of the optical cat is to convert the signal of the telephone line into the signal of the network cable for the computer to surf the Internet;
The function of the router is to connect multiple computers through a network cable to realize virtual dial-up Internet access, with automatic identification of data packet sending and address allocation, and a firewall function. Among them, multiple computers share a broadband account, which affects the Internet;
The role of the switch is to connect multiple computers with a single network cable to achieve simultaneous Internet access. There is no router function, but each computer has its own broadband account, and Internet access does not affect each other.
Optical modems are generally used to access optical fibers at home; switches and routers work in a local area network, but switches work at the data link layer, while routers work at the network layer.
1. When the home is connected to the optical fiber, just choose the optical modem and router, because the number of home network computers is small, the router can meet the needs of users;
2. When the number of computer connections exceeds the router interface (that is, the construction of corporate networks, local area networks, etc.), routers and switches must be selected at the same time, and the switches must be used for port expansion to meet user needs.
A full understanding of the differences between optical modems, switches, and routers will help you find more suitable equipment for your own network. I hope that through the introduction of optical modems, switches, and routers in this article, you will be able to better understand the difference between optical modems, switches and routers, so as to select appropriate equipment for network deployment.