SNCP is a unidirectional network with two rings, one ring used as the working ring and the other as the protection ring. The
same signal flows through both rings, one clockwise and the other counterclockwise. It is called SNCP because monitoring is
done at the path layer. A node receives two copies of the electrical signals at the path layer, compares them, and chooses
the one with the better quality. If part of a ring between two ADMs fails, the other ring still can guarantee the continuation
of data flow. SNCP, like the one-plus-one scheme, has fast failure recovery.
SNCP Path Protection is supported at VC level and STM level.
Once a signal fail condition or a signal degrade condition is detected, the hardware initiates an interrupt to software that
switches from the working path to the protection path. Non-revertive options are valid for SNCP path protection.
Note
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1X OC-192 and 8X OC-48 interface modules only supports the non-revertive option. The non-revertive option is the default mode.
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The maximum scale supported on SNCP at system level is 1000 circuits.