user manual
Table Of Contents
- Cisco ONS 15454 SDH Reference Manual
- Contents
- About this Guide
- Shelf and FMEC Hardware
- Common Control Cards
- Electrical Cards
- Optical Cards
- Ethernet Cards
- Storage Access Networking Cards
- Card Protection
- Cisco Transport Controller Operation
- Security and Timing
- Circuits and Tunnels
- SDH Topologies and Upgrades
- CTC Network Connectivity
- Alarm Monitoring and Management
- Ethernet Operation
- Hardware Specifications
- A.1 Shelf Specifications
- A.2 SFP Specifications
- A.3 General Card Specifications
- A.4 Common Control Card Specifications
- A.5 Electrical Card and FMEC Specifications
- A.5.1 E1-N-14 Card Specifications
- A.5.2 E1-42 Card Specifications
- A.5.3 E3-12 Card Specifications
- A.5.4 DS3i-N-12 Card Specifications
- A.5.5 STM1E-12 Card Specifications
- A.5.6 BLANK Card
- A.5.7 FMEC-E1 Specifications
- A.5.8 FMEC-DS1/E1 Card Specifications
- A.5.9 FMEC E1-120NP Card Specifications
- A.5.10 FMEC E1-120PROA Card Specifications
- A.5.11 FMEC E1-120PROB Card Specifications
- A.5.12 E1-75/120 Impedance Conversion Panel Specifications
- A.5.13 FMEC-E3/DS3 Card Specifications
- A.5.14 FMEC STM1E 1:1 Card Specifications
- A.5.15 FMEC-BLANK Card Specifications
- A.5.16 MIC-A/P Card Specifications
- A.5.17 MIC-C/T/P Card Specifications
- A.6 Optical Card Specifications
- A.6.1 OC3 IR 4/STM1 SH 1310 Card Specifications
- A.6.2 OC3 IR/STM1 SH 1310-8 Card Specifications
- A.6.3 OC12 IR/STM4 SH 1310 Card Specifications
- A.6.4 OC12 LR/STM4 LH 1310 Card Specifications
- A.6.5 OC12 LR/STM4 LH 1550 Card Specifications
- A.6.6 OC12 IR/STM4 SH 1310-4 Card Specifications
- A.6.7 OC48 IR/STM16 SH AS 1310 Card Specifications
- A.6.8 OC48 LR/STM16 LH AS 1550 Card Specifications
- A.6.9 OC48 ELR/STM16 EH 100 GHz Card Specifications
- A.6.10 OC192 SR/STM64 IO 1310 Card Specifications
- A.6.11 OC192 IR/STM64 SH 1550 Card Specifications
- A.6.12 OC192 LR/STM64 LH 1550 Card Specifications
- A.6.13 OC192 LR/STM64 LH ITU 15xx.xx Card Specifications
- A.7 Ethernet Card Specifications
- A.8 Storage Access Networking Card Specifications
- Administrative and Service States
- Network Element Defaults
- Index

11-15
Cisco ONS 15454 SDH Reference Manual, R5.0
April 2008
Chapter 11 SDH Topologies and Upgrades
11.3 Subnetwork 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 coming through Node D.
Figure 11-14 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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