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Cisco ONS 15600 SDH Reference Manual, Release 9.0
78-18400-01
Chapter 3 Card Protection
3.2 Unprotected Ports
Figure 3-1
ONS 15600 SDH in a 1+1 Protected Configuration
With 1+1 protection, any port can be assigned to protect the traffic of a corresponding working port. A
working port must be paired with a protect port of the same type, for example, an STM-16 port must be
paired with another STM-16 port.
1+1 span protection can be either revertive or nonrevertive. With nonrevertive 1+1 protection, when a
span failure occurs and the signal switches from the working port to the protect port, the signal stays
switched to the protect port until it is manually switched back. Revertive 1+1 protection automatically
switches the signal back to the working port when the failure condition on the working port is cleared.
For more information about protection schemes and how to create and modify them with Cisco Transport
Controller (CTC), refer to the
Cisco ONS 15600 SDH Procedure Guide
.
3.2 Unprotected Ports
Unprotected ports are not included in a protection scheme; therefore, a port failure or a signal error can
result in data loss if no path level protection (SNCP) exists. Because no bandwidth lies in reserve for
protection, unprotected schemes maximize the available ONS 15600 SDH bandwidth.
shows
the ONS 15600 SDH in an unprotected configuration. All ports are in a working state.
TSC
Working STM-N
Protect STM-N
SSXC SSXC TSC
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