Hitachi US7070447-001 manual Chapter FDDI Concepts, 1. HS150 on an FDDI network

Chapter 12

FDDI Concepts

FDDI employes a dual ring topology using two counter-rotating fiber rings: a primary and secondary. Data travels on the primary ring while the secondary backup ring is utilized if the primary ring fails. The data rate is 100 Mbps based on a timed-token access method. The total length of the ring can extend up to 200 kilometers with nodes spaced up to 2 kilometers over multimode fiber.

Dual Ring

￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿ Concentrator

DAS HS 150 SAS HS 150

Figure 12-1. HS150 on an FDDI network

US7070447-001, Rev 01 12-1