A Hub provides the opportunity to separate the physical structure from the logical structure on Ethernet. A Hub can be used to combine several network subscribers into a star structure (physically). However, the bus structure is retained as the logical structure. Hubs may also be referred to as star couplers. Data packets received at one Port on the Hub will be transmitted to all
Ports on the Hub. As well as Hubs for 10BaseT (10 MBit/s) and 100BaseT (100 MBit/s), there are also Autosensing Hubs. These automatically detect whether the connected end device is operating at 10 or 100 MBit/s. Autosensing Hubs can be used to incorporate older 10BaseT devices into new 100BaseT networks without problem.