Cisco ONS 15454 Reference Manual page 388

12.2 12.2.2 Four-Fiber BLSRs
Figure 12-5
Node 3
Ring switching
•
the working and protect fibers fail on the same span. In a ring switch, traffic is routed to the protect
fibers throughout the full ring.
Cisco ONS 15454 Reference Manual, R7.0.1
12-8
Four-Fiber BLSR Span Switch
Node 0
Span 4
Span 5
OC-48 Ring
Span 6
Span 3
Node 2
(Figure 12-6) occurs when a span switch cannot recover traffic, such as when both
Chapter 12
Span 1
Span 8
Node 1
Span 7
Span 2
= Working fibers
= Protect fibers
SONET Topologies and Upgrades
OL-9217-01