Cisco ONS 15600 Reference Manual page 157

Chapter 8 SONET Topologies and Upgrades
Figure 8-6
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.
Four-Fiber BLSR Span Switch
Node 0
Span 4
Span 5
OC-48 Ring
Span 6
Span 3
Node 2
(Figure 8-7) occurs when a span switch cannot recover traffic, such as when both
Span 1
Span 8
Node 1
Span 7
Span 2
= Working fibers
= Protect fibers
Cisco ONS 15600 Reference Manual, R8.0
8.3.2 Four-Fiber BLSRs
8-7