Information Technology Reference
In-Depth Information
Figure5-5
Failed Wiring, Ring Recovery Configuration
Station 1
MAC
B
A
Station 4
Station 2
Ring wrap
A
B
MAC
MAC
B
A
Ring wrap
Failed wiring
AB
MAC
Station 3
As FDDI networks grow, the possibility of multiple ring failures grows. When two ring failures occur,
the ring is wrapped in both cases, effectively segmenting the ring into two separate rings that cannot
communicate with each other. Subsequent failures cause additional ring segmentation.
Optical bypass switches can be used to prevent ring segmentation by eliminating failed stations from the
ring. This is shown in Figure 5-6.
