Repeaters are the most basic form of forwarding device. They associate with Layer 1 as they do not have the ability to inspect the content of the headers. They simply regenerate the exact copy of the electrical signal. They are primarily used to extend the distance of cable run. They are seldonly used now due to advance of fibre optics that spans great distance.
Hub, or concentrator are simply multiport repeaters. The concept is the same. A signal delivered to any port on the hub is regenerated and forwarded to all ports. Again, there is no examination of frame. Hub is generally deployed in small LAN. When the number of nodes increases, perform degrades significantly as bandwidth are contended.
Ethernet is a baseband medium, meaning only 1 signal will be transmitted at any one time. When 2 nodes attempt to transmit at the same time, collision results. The nodes will reattempt to transmit at a later time. Therefore, hubs and repeaters in a network form a collison domain.
As the size of network grow, the collision domain becomes less efficent. Solution needs to partition the collision domain.
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