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Cisco ONS 15454 SDH Reference Manual, R5.0
April 2008
Chapter11 SDH Topologies and Up grades
11.3 Subnetw ork Connection Protection
The same signal is also sent on the protect traffic path through Node D. If a fiber break occurs
(Figure 11-14), Node C switches its active receiver to the protect signal comi ng through Node D.
Figure11-14 SNCP Ring with a Fiber Break
Because each traffic path is transported around the entire ring, SNCP rings are best suited for networks
where traffic concentrates at one or two locations and is not widely distributed. SNCP ring capacity is
equal to its bit rate. Services can originate and terminate on the same SNCP ring, or they can be passed
to an adjacent access or interoffice ring for transport to the service-terminating node.
Span 1
Span 2
Span 3
Span 4
Span 8
Span 7Span 6
Span 5
Fiber
break
Source
Destination
ONS 15454 SDH
Node A
ONS 15454 SDH
Node B
ONS 15454 SDH
Node C
ONS 15454 SDH
Node D
= Fiber 1
= Fiber 2
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