Datasheet

7-2
Cisco ONS 15454 SDH Reference Manual, R7.0
October 2008
Chapter 7 Card Protection
7.1.2 1:N Protection
Figure 7-1 ONS 15454 SDH Cards in a 1:1 Protection Configuration
7.1.2 1:N Protection
1:N protection allows a single card to protect several working cards. An E1-N-14 card protects up to four
E1-N-14 cards, and a DS3i-N-12 card protects up to four DS3i-N-12 cards.
Currently, 1:N protection operates only at the E-1, DS-3, and DS-1 levels. The 1:N protect cards must
match the levels of their working cards. For example, an E1-N-14 protects only E1-N-14 cards, and a
DS3i-N-12 protects only DS3i-N-12 cards.
The physical E-1, DS-3, or DS-1 ports on the ONS 15454 SDH FMEC cards use the working card until
the working card fails. When the node detects this failure, the protect card takes over the physical E-1,
DS-3, or DS-1 electrical interfaces through the relays and signal bridging on the backplane. Figure 7-2
shows the ONS 15454 SDH in a 1:N protection configuration. Each side of the shelf assembly has only
one card protecting all of the cards on that side.
83626
1:1 Protection
FMEC FMEC FMEC FMEC FMEC
MIC-A/P
MIC-T/C/P
FMEC FMEC FMEC FMEC FMEC
Timing, Comm., and Control Cross Connect
Cross Connect
Timing, Comm., and Control Working
Working
Working
(not electric)
Working
(not electric)
Working
Working
Protect
Protect
Working
Working
Protect
Protect
AIC-I (optional)
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