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Cisco ONS 15454 Reference Manual, R7.0
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Chapter 7 Card Protection
7.4 7.4 Unprotected Cards
installed side by side in the node. A working card must be paired with a protect card of the same type
and number of ports. For example, a four-port OC-3 must be paired with another four-port OC-3, and an
eight-port OC-3 must be paired with another eight-port OC-3. You cannot create an optimized 1+1
protection group if the number of ports do not match, even if the OC-N rates are the same.
The protection takes place on the port level, and any number of ports on the protect card can be assigned
to protect the corresponding ports on the working card. For example, on a four-port card, you can assign
one port as a protection port on the protect card (protecting the corresponding port on the working card)
and leave three ports unprotected. Conversely, you can assign three ports as protection ports and leave
one port unprotected. With 1:1 or 1:N protection (electrical cards), the protect card must protect an entire
slot. In other words, all the ports on the protect card are used in the protection scheme.
7.4 Unprotected Cards
Unprotected cards are not included in a protection scheme; therefore, a card failure or a signal error
results in lost data. Because no bandwidth lies in reserve for protection, unprotected schemes maximize
the available ONS 15454 bandwidth. Figure 7-8 shows the ONS 15454 in an unprotected configuration.
All cards are in a working state.
Figure 7-8 ONS 15454 in an Unprotected Configuration
7.5 External Switching Commands
The external switching commands on the ONS 15454 are Manual, Force, and Lockout. If you choose a
Manual switch, the command will switch traffic only if the path has an error rate less than the signal
degrade (SD) bit error rate threshold. A Force switch will switch traffic even if the path has SD or signal
fail (SF) conditions; however, a Force switch will not override an SF on a 1+1 protection channel.
Unprotected
TCC
Cross-connect
AIC (Optional)
Cross-connect
TCC
Working
Working
Working
Working
Working
Working
Working
Working
Working
Working
Working
Working
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