Cisco Systems Cisco ONS 15310-MA, ONS 15310-CL manual RPR Framing Process, 15-4

Chapter 15 Configuring Resilient Packet Ring on the ML-Series Card

Understanding RPR

Note

Note

Note

Figure 15-2 RPR Ring Wrapping

Ring Wrap

Fiber Cut

ML-Series RPR

Ring Wrap

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In case of a ring failure, the ML-Series cards connected to the failed section of the RPR detect the failure through the SONET path alarms. When any ML-Series card receives this path-AIS signal, it wraps the POS interface that received the signal.

If the POS interfaces on the ML100T-8 cards on either 15310MA or 15310CL receives the SF-P condition, then the SPR ring does not wrap.

If the carrier delay time is changed from the default, the new carrier delay time must be configured on all the ML-Series card interfaces.

ML-Series card POS interfaces normally send an alarm for signal label mismatch failure in the STS path overhead (PDI-P) to the far end when the POS link goes down or when 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 (GFP)-loss of frame delineation (LFD), GFP client signal fail (CSF), virtual concatenation (VCAT)-loss of multiframe (LOM), or VCAT-loss of sequence (SQM).

RPR Framing Process

The ML-Series card uses a proprietary RPR frame and HDLC or GFP-F framing. It attaches the RPR frame header to each Ethernet frame and encapsulates the RPR frame into the SONET payload for transport over the SONET topology. The RPR header is removed at the egress ML-Series card. Figure 15-3illustrates the RPR frame.

Cisco ONS 15310-CL, ONS 15310-MA, and ONS 15310-MA SDH Ethernet Card Software Feature and Configuration Guide, R9.1 and R9.2

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