A network hub, otherwise called a hub, is a controller that combines several Ethernet devices into a single network segment. Devices connect to the hub using fiber optic or coaxial cable. Applied for this and
twisted pair. The principle of operation of the hub is simple: it multiplies all incoming data packets and sends them to all ports connected to it.
The network hub, like other types of hubs, has its own qualitative characteristics. Firstly, the performance and price of the hub depend on the number of ports. The more Ethernet devices connected to it, the higher the performance and cost of the hub. Usually the hub is equipped with an even number of connectors, the number of which varies from four to 24, but some types have five outputs. The number of ports can be increased by cascading several hubs. For this connection, each hub has a special connector.
It has a network hub and another important feature - the speed of copying and transmitting data packets. Some hubs are capable and
Change your speed in the range from ten to one hundred megabits per second. In such devices, it changes in two ways: either automatically, or manually, using the switch. In this case, the set speed applies to all active ports. Hubs differ in the type of network media. As a rule, this role goes either to a
fiber-optic cable or a twisted pair
cable , but there are hubs that support other types of carriers. There are also hubs for mixed types, for example, supporting a “hybrid” twisted pair with a coaxial cable.
The principle of operation of the hubs is very imperfect. The network hub copies the data packet that came from one channel to all other channels connected to it, which greatly reduces the speed of the Internet, since all web devices connect to the network through a common channel. If two packets are copied at the same time, a collision can occur, that is, a collision of the same signals, in which some data is lost. Some types of hubs are protected against too many collisions. As a rule, they are based on twisted pair. In the event of a failure, this isolates a single
device, while a network hub connected through a
coaxial cable disconnects the entire segment immediately.
It affects the principle of the hub and data security. If the computer enters the local network, the data packets of one system reach all other nodes. Because of this, all personal settings of social networks, passwords for blogs, forums and other private data can become known to all members of this network. For these reasons, the USB network hub is increasingly being replaced by a network switch or switch. This device, which received the erroneous title of “intelligent hub”, distinguishes the MAC addresses of computers in the network and sends data only to the port selected by the user. Packets go through the buffer, which eliminates collisions, line congestion and data leakage. Due to their reliability and low price, switches are increasingly used in home systems, while hubs are almost no longer sold.