3Com 16 Plus User Manual page 18

Priority Queuing is the ability of a network to give and
maintain certain throughput levels for different applications
depending on the priority assigned to that application. At
excessive loads a packet with a higher priority will take a
greater precedence over a lower prioritised packet.
Automatic MDI / MDIX this feature automatically detects
which wiring practice that has been followed with regard to
the TP cable, ie if the TP cable is a 'straight through' wired
cable or a 'crossover' wired cable. The automatic MDI /
MDIX feature within the Switch will detect and compensate
accordingly.
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