1, network adapter (network card)

The network card is a network component working in the link layer, and it is the interface connecting computers and transmission media in the local area network. It can not only realize the physical connection and electrical signal matching with transmission media in LAN, but also involve the functions of sending and receiving frames, encapsulating and unpacking frames, media access control, data encoding and decoding, data caching and so on.

2. Modem

The Modem we often say is actually the abbreviation of modulator and demodulator, which is called modem in Chinese. Some people affectionately call it "cat" according to the homonym of Modem.

3. Repeater

Repeater is a connecting device above the physical layer of the network. It is suitable for the interconnection of two same networks, and its main function is to extend the network transmission distance by forwarding or forwarding data signals. Repeater is a network device that regenerates and recovers signals: the physical layer device of OSI model.

4. Center

Hub is called "hub" in English. "Hub" means "center". The main function of the hub is to regenerate, shape and amplify the received signal, so as to expand the transmission distance of the network, and at the same time concentrate all nodes on the node centered on it. It works in the first layer of the OSI (open system interconnect) reference model, that is, the "physical layer". Hub, like network card, network cable and other transmission media, belongs to the basic equipment in local area network, and adopts CSMA/CD (carrier sense multiple access technology with collision detection) medium access control mechanism. Each interface of the hub only sends and receives bits. When it receives 1, it forwards 1, and when it receives 0, it forwards 0 without collision detection.

5. Bridge

A bridge is like a clever repeater. A repeater receives a signal from one network cable, amplifies it and sends it to the next cable. Comparatively speaking, bridges are more sensitive to information uploaded from checkpoints. Bridge is a technology of forwarding frames, which can isolate conflicts according to MAC partition blocks. Bridges connect multiple network segments at the data link layer.

Step 6 convert

Switch, which means "switch", is a network device used for electric (optical) signal forwarding. It can provide a dedicated electrical signal path for any two network nodes accessing the switch. The most common switch is an Ethernet switch. Other common ones are telephone voice switch and optical fiber switch.

7. Router

A router is a device that connects a local area network and a wide area network in the Internet. It will automatically select and set the route according to the channel conditions, and send signals in turn by the best path.

8. door

Gateways are also called gateways and protocol converters. Gateway realizes network interconnection above the network layer, and is the most complex network interconnection equipment, which is only used for interconnection of two networks with different high-level protocols. Gateway can be used for wide area network interconnection and local area network interconnection. Gateway is a computer system or equipment that plays an important role in conversion.

A complete campus network construction mainly includes two contents: technical scheme design; Resource construction of application information system.

The technical scheme design mainly includes: structured wiring and equipment selection, network technology selection, etc. The construction of application information system resources mainly includes internal information resources construction and external information resources construction.