Digital modem (cat)
Digital modem original name modem , but since then there are the optical modem , so prefix the word to show distinction.
Early no fiber, are taking the Internet phone line.
"Cat", the official name of the modem , it is the modulator and demodulator integration of the product, wherein the modulator is responsible for converting the digital computer signals into analog signals, then the demodulator telephone line transmission may be transmitted on the telephone line It converts an analog signal into a digital signal the computer can recognize.
In this way the computer in the "cat" with the help of the telephone line signal transmission, the formation of the early network.
Early network because it is transmitted over the phone line, all of the bandwidth is relatively small, the performance of the Internet is slow, then people invented a faster transmission of signals materials, optical fiber!
Optical modem (-cat)
Understanding of the above "cat", "Light Cat" on a good understanding.
"Light Cat" official names optical modem , since it is the modem to be divided into modulation and demodulation section portion.
- Modulation section: converting the digital signal into an optical signal
- Demodulating section: converting the optical signal into a digital signal
Now most families have a fiber to the home, above, it is the most basic home network map.
- POWER: power to light cat
- OPTICAL: Fiber to access
- LAN: generally do not select directly to the computer, so that only one device can be connected, asking too much, usually to buy a wireless router, and then light the cat's LAN port to the wireless router's WAN port on this way , can support multiple devices online.
Now go through broadband, operators often provide a "light cat" & Wireless router combo products, eliminating the need for users to configure the wireless router trouble.
Wireless Router
Wireless routers are we ordinary people the most common network devices, note that not all routers with external antenna, many routers are built-in antenna, and with good results.
- POWER: power to the router
- WAN: Use a network cable to the light cat LAN port on
- LAN: General network cable is not connected to the desktop wireless card
Like the modem is a modulator , a demodulator combo, wireless router we often are more combination contact device
- It is a router that supports NAT function, static routing
- It is a switch, generally comes with 3,4 port Ethernet switch (LAN port)
- It is also a wireless AP, the wireless signal into a wired can
- It is also firewall / behavior management, but weaker function, performance almost nothing
Wireless router has a very important issue, once the larger, more complex spatial structure, walls pay more coverage on an issue, some places may signal poor, even in some places there is no direct signal.
One might expect to buy more than one wireless router, in fact, this is not a good solution, in which there will be many problems, such as each router is a separate, independent management needs. Each router must be equipped with a power outlet cable jack and the like.
More mature solution is integrated PoE · AC + wireless router AP
Integrated PoE · AC + wireless router AP
Integrated PoE · AC + router TP-LINK's wireless networking solutions introduces AP video
AC
When it comes to above using multiple wireless routers, because each router is independent, each router needs to be configured independently, independent management, more than one number is not very convenient. So people think, simply to configure, manage functions alone carry out a special device to the genus to unified management, this device is AC
Full access controller AC (Wireless AccessPoint Controller) is a network device for controlling a controlled centralized wireless LAN AP, a wireless core network is responsible for managing all of the wireless AP in a wireless network, the AP management comprising : delivering the configuration, modify the configuration parameters, radio intelligent management, security access control. (Currently in circulation all AC and AP are identical to one another vendor management)
As shown,
POE power supply module
The network device is typically required power plug, as described above routers, but supports POE powered device may be transmitted via a power line network. At this time, i.e., data transmission and cable transmission power.
As shown, POE power supply module end Subsequently, one end of the cable and then
POE Switch
POE switch is the switch with POE power supply module, since the POE power supply module can only transmit power, so it is rarely used alone, and is combined with the switch.
As shown, this is a POE switch that interconnects all of the insertion port of the device up to the first four ports can transfer data and power supply devices POE last only transmit data to a port (left non POE equipment)
PoE · AC integrated router
PoE · AC integrated router built-in AC (Wireless Controller) + POE function, set POE router and switch functions into one. Such advantage is that no devices arranged separate AC, POE switches, plug and play.
FIG, 4 LAN ports can give four PoE devices and transmission of data, the WAN port to the LAN port on the cat light, and can be plugged.
Configuration with the wireless router like, except that its transmitter in the wireless AP , the wall of which is connected through the network cable and wireless AP
Wireless AP
Full wireless AP wireless access point (WirelessAccessPoint), capable of wired / wireless radio signal conversion and signal receiving / transmitting apparatus can be called a wireless AP , such as Bluetooth / IR, but under the circumstances unless otherwise specified, refers to a default 802.11 the wireless AP, that is familiar to everyone WIFI.
The following panel of wireless AP POE power supply section, it is long like this
Cable looks like the wall socket, but see the Wi-Fi but not expressed, it is actually give transmitting wireless signals, and different from the wireless router needs a separate power supply, POE power supply section but may be powered by the wireless AP cable
installation
It can be seen that the original wall cable outlet into it
Fat AP, thin AP
Fat AP : do not need AC Management, AP can work independently, such as our wireless router can be seen as a fat AP
Thin AP : need to use the AC with the AP, can not work alone
But now the most AP integrally fat or thin, and provides the control mode is switched to start
to sum up
Integrated PoE · AC + wireless router AP This model can be considered to carry out the management side of the router, and with a plurality of transmitting end, achieve full coverage of the signal
However, this model has a hard condition, requires prior installation in the desired room embedded wireless AP cable. If not embedded, the latter can only traces on the wall.
Mesh MANET
H3CMesh Ad Hoc Networks Introduction Video
If the conditions are not installed PoE · AC integrated router + wireless AP, Mesh ad hoc network is also a good choice.
Mesh networking router later, in which an optical pick cats, several other places in bad signal, plugged in, a plurality of routers via a radio signal will be composed of a large network.
FIG comparison with traditional networking
Mesh ad hoc network with a wireless router to use almost the same, cut pan with high, does not depend on other things, it is a great networking