media-dependent interface (MDI)
The normal operation of ethernet ports on a hub. In this mode, the mapping of the wire pairs in the hub port is in a normal configuration. Some hubs provide a media-dependent interface/media-dependent interface, crossover switch. This switch is usually associated with a particular port. With this switch set correctly, you can connect a network device to the associated port using a straight-through ethernet cable rather than a crossover ethernet cable.