FDDI uses two rings that are independent of each other and transmit data in opposite directions. A secondary ring provides an alternate data path in the event a fault occurs on the primary ring. FDDI stations incorporate this secondary ring into the data path to route traffic around the fault.

Why does FDDI use counter rotating rings?

The counter-rotating secondary ring can carry data in the opposite direction, but is more commonly reserved as a backup in case the primary ring goes down. This provides FDDI with the degree of fault tolerance necessary for network backbones.

What is the role of inner ring in FDDI?

It provides high data rate of 100 Mbps and can support thousands of users. ... It contains two token rings, a primary ring for data and token transmission and a secondary ring that provides backup if the primary ring fails. FDDI technology can also be used as a backbone for a wide area network (WAN).