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

11-14
Cisco ONS 15454 SDH Reference Manual, R5.0
April 2008
Chapter 11 SDH Topologies and Upgrades
11.3 Subnetwork Connection Protection
CTC automates ring configuration. SNCP ring network traffic is defined within the ONS 15454 SDH on
a circuit-by-circuit basis. If an extended SNCP ring mesh network circuit is not defined within a 1+1 or
MS-SPRing line protection scheme and path protection is available and specified, CTC uses an SNCP
ring as the default protection mechanism.
An SNCP ring circuit requires two DCC-provisioned optical spans per node. SNCP ring circuits can be
created across these spans until their bandwidth is consumed.
The span bandwidth consumed by an SNCP ring circuit is two times the circuit bandwidth because the
circuit is duplicated. The cross-connection bandwidth consumed by an SNCP ring circuit is three times
the circuit bandwidth at the source and destination nodes only. The cross-connection bandwidth
consumed by an intermediate node has a factor of one.
The SNCP ring circuit limit is the sum of the optical bandwidth containing 84 section data
communication channels (SDCCs) or 28 line data communication channels (LDCCs), divided by two.
The spans can be of any bandwidth from STM-1 to STM-64.
Figure 11-13 shows a basic SNCP ring configuration. If Node A sends a signal to Node C, the working
signal travels on the working traffic path through Node B.
Figure 11-13 Basic Four-Node SNCP Ring
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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