They are physical layer devices that connect network devices in a star or ring topology.
They amplify and repeat signals received through one port out all other ports regardless of the destination.
Token Ring hubs are multistation access units (MAUs). MAUs can be joined together through dedicated Ring In (RI) and Ring Out (RO) ports to build a larger ring.
Hubs provide internal crossover circuits and use uplink ports to form a hierarchical star.
