Figure 17-2 Cisco Proprietary Rpr Ring Wrapping - Cisco ONS 15454 SDH Configuration Manual

Ring Wrapping
Figure 17-2
Ring Wrap
In case of a ring failure, the ML-Series cards connected to the failed section of the Cisco proprietary
RPR detect the failure through the SONET/SDH path alarms. When any ML-Series card receives this
path-AIS signal, it wraps the POS interface that received the signal.
Convergence times might exceed 50 ms in the case of multiple failures in the same ring, if traffic passes
Note
through an ML-Series card configured with DRPRI (in active mode) during the reloading of the ML-Series
card, or in the case of mismatched microcode images on ML-Series cards.
If the carrier delay time is changed from the default, the new carrier delay time must be configured on
Note
all the ML-Series card interfaces, including the SPR, POS, and Gigabit Ethernet or Fast Ethernet
interfaces.
ML-Series card POS interfaces normally send an alarm for signal label mismatch failure in the
Note
ONS 15454 STS path overhead (PDI-P) to the far end when the POS link goes down or when
Cisco proprietary RPR wraps. ML-Series card POS interfaces do not send PDI-P to the far end when
PDI-P is detected, when a remote defection indication alarm (RDI-P) is being sent to the far end, or when
the only defects detected are generic framing procedure loss of frame delineation (GFP-LFD), generic
framing procedure client signal fail (GFP-CSF), virtual concatenation loss of multiframe (VCAT-LOM),
or virtual concatenation loss of sequence (VCAT-SQM).
Cisco ONS 15454 and Cisco ONS 15454 SDH Ethernet Card Software Feature and Configuration Guide, R8.0
17-4
Cisco proprietary RPR Ring Wrapping
Fiber Cut
ML-Series RPR
Chapter 17 Configuring Cisco Proprietary Resilient Packet Ring
Ring Wrap