Ethernet HUB

The Hub is used in Ethernet base 10 and base 100 (not Gigabit Ethernet), in star topologies using RJ45 connection. This network equipment amplifies the signal to return to all PC and connected devices (a switch does it refers to only one port, that of the recipient). In the case of local networks by the large number of PCs connected or the amount of transferred data stream, the HUB is replaced by switch (Usually Full duplex). In the case of a HUB, a received message is sent to all ports connections slowing the entire network.

Other features of Hubs

Hub's Ethernet-based 10: Number of connection variable port inverter (This allows you to connect two Ethernet hubs to one another, avoiding the use of a RJ45 crossover cable), a coaxial connection. By connection, there is a led indicating the connection to a map network and an LED indicating collisions (one per port or Ethernet all). This indicates the status of all connections.

Ethernet Hub's base 100: Variable number of connections, port switch (connection two hubs to one another), never coaxial connection 10 Base 2. There is a LED port connection and collision LEDs per channel (or overall), for 10/100, two LEDs indicate the speed for each port (10 base T and 100 base T).

Depending on the speed, the HUB maximum number of cascaded (Connected port to port, no stackable types) is four devices in two 10 base T Ethernet and two for the 100 base T. This limitation is related to maximum propagation of a signal before disappearance and that of collision detection: a collision could not be detected in time, a second emitting equipment into thinking that the way is free, creating frames called incomplete RUNT or overlaying the two data communications.

All are Hub half duplex and can transmit and receive simultaneously (including several network ports), the clear channel detecting collisions on the Ethernet cable.

Associated definitions: Network