Sun Microsystems 1.0 - Manual (Page 81)

FDDI Network Architecture 55
6
FDDI Network Architecture
A typical FDDI network is based on a dual, counter-rotating ring, as illustrated
in Figure 6-3. Each FDDI station is connected in sequence to two rings
simultaneously—a primary ring and a secondary ring. Data flows in one
direction on the primary ring, and in the other direction on the secondary ring.
Figure 6-3 Basic FDDI Network Architecture
The secondary ring serves as a redundant path. It is used during station
initialization, and may be used as a backup to the primary ring in the event of
a station or cable failure. When a failure occurs, the dual-ring is “wrapped”
around to isolate the fault and to create a single, one-way ring. The
components of a typical FDDI network and the failure recovery mechanism are
described in more detail in the following sections.
FDDI station
FDDI station FDDI station
FDDI station
Primary ring
Secondary ring