Cats, routers, switches, and PCs

Reprint: http://duanzw102.blog.163.com/blog/static/161838173201392431722650/

A cat is a modem and is a network provider, such as a dial-up tool provided by a telecommunications company. Routers, generally dlink or tplink, are users themselves in their own home network, a number of computers share an external network cable line tool. switch, mainly only to increase the number of ports, the general router only provides 4 intranet ports, so that there are 1 external network ports, routers can be used when the switch with 1, the cat and the router to distinguish the full name of the cat modem, in China is the ADSL user access point necessary hardware, Can translate the digital signal of the computer into a pulse signal which can be transmitted along the ordinary telephone line, and these pulses can be received by another modem on the other end of the line and translated into a computer-readable language. This simple process completes the communication between the two computers, which is simply to realize the conversion of digital signal and pulse signal. Routers are devices that select routes for information flow or data grouping to connect two different networks. The difference is: 1, the cat is not DHCP function, the router has. 2, the cat does not have the route choice function. 3, the router has its own IP address, the cat did not. 4, the router generally has the function of the switch, the cat does not have. 5, the router generally has an access port, a plurality of port, the cat general access port one. 6, the router access port signal is a digital signal, the cat's access port is the pulse signal, the port is a digital signal ....　     There are a lot of differences. Individual users compared to the multi-broadband access mode is ADSL, on the ADSL access to a simple explanation. Now the purchase of ADSL mostly has a routing function (a lot of time manufacturers at the factory when the routing function is blocked, because most of the telecommunications installation is not enabled routing function, DHCP enabled. Turn on the ADSL routing function), if the personal Internet or a few units via ADSL itself can be, if the computer is more than you only need to purchase one or more hubs or switches. 2. Differences between switches and routersFirst of all, the switch (aka Interchange Hub) function can be simply understood to connect some machines together to form a local area network. The difference between routers and switches is that it is useful to connect different network segments and find the most appropriate path for data transfer in the network.

Switch is a kind of network device which can complete the function of encapsulating and forwarding packets based on the identification of MAC (network card's hardware address). The switch can "learn" the MAC address and store it in the internal Address table, by establishing a temporary switching path between the originator of the data frame and the target receiver, so that the data frame is directly from the source address to the destination site. Today's switches are divided into: two-layer switches, three-layer switches, or higher-level switches. Layer three switches can also have routing capabilities, and faster forwarding rates than low-end routers. Its main features are: one-time routing, multiple forwarding.

Routers (Router), also known as the selector, are devices that interconnect at the network level. It is more complex than a bridge and has greater flexibility. Routers have a stronger heterogeneous network interconnection capability, including LAN and WAN connectivity objects. In the past, routers have been used for wide-area networks in recent years, and because of the high performance of routers, the price has dropped to close to the bridge, so routers are used more and more in LAN interconnection. A router is a network device that connects multiple networks or segments, which can "translate" data between different networks or segments so that they can "read" each other's data to form a larger network. Routers have two typical functions, namely data channel function and control function. Data channel functions include forwarding decision, backplane forwarding and output link scheduling, which is usually done by specific hardware, and the control function is usually implemented by software, including information exchange between neighboring routers, system configuration, system management, etc.

3. Connection

The entrance line to connect the cat, the cat WAN port to connect the WAN port of the router, the router can complete on the cat dial landing. Router LAN port to the computer or switch, switch can not use, home routers generally have 4 LAN port, so if the computer under 4, you can directly connect the computer to the router LAN port, if the number of computers more than 4, router LAN port can be connected to the switch WAN port to increase the number of network ports, thereby using the switch LAN port to connect multiple computers. If the computer directly connected to the cat, you need to dial on the computer, if you use a router, and the router in accordance with the instructions configured, after the successful configuration, the router completes the dial, the computer connected to the router on the Internet, do not dial.

Cats, routers, switches, and PCs