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Cisco ONS 15454 SDH Reference Manual, R5.0
April 2008
Chapter3 Electrical Cards
3.5.1 DS3i-N-12 Card Functionality
Figure3-4 DS3i-N-12 Faceplate and Block Diagram
3.5.1 DS3i-N-12 Card Functionality
The DS3i-N-12 can detect several different errored logic bits within a DS-3 frame. This function lets the
ONS 15454 SDH identify a degrading DS-3 facility caused by upstream electronics (DS-3 Framer). In
addition, DS-3 frame format autodetection and J1 pat h trace are supported. By monitoring additional
overhead in the DS-3 frame, subtle network degradations can be detected.
The DS3i-n-12 can also aggregate DS3 and E1 traffic and transport it between SONET and SDH
networks through AU4/STS 3 trunks, with the ability to add and drop DS3s to an STS3 trunk at
intermediate nodes.
The following list summarizes the DS3i-N-12 card features:
•Provisionable framing format (M23, C-bit, or unframed)
•Autorecognition and provisioning of incoming framing
•VC-3 payload mapping as per ITU-T G.707
•Idle signal (“1100”) monitoring as per Telcordia GR-499-CORE
•P-bit monitoring
134379
B
a
c
k
p
l
a
n
e
DS3
ASIC
Flash
uP bus
SDRAM
BTC
ASIC
Line
Interface
Unit #1
main DS3-m1
protect DS3-p1
Line
Interface
Unit #1
main DS3-m12
protect DS3-p12
Processor
OHP
FPGA
BERT
FPGA
FAIL
ACT/STBY
SF
DS3I- N
12