User manual

Table Of Contents

14-4

Cisco ONS 15310-CL and Cisco ONS 15310-MA Ethernet Card Software Feature and Configuration Guide R8.5

78-18133-01

Chapter 14 Configuring Resilient Packet Ring on the ML-Series Card

Understanding RPR

Figure 14-2 RPR Ring Wrapping

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.

Note 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.

Note 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.

Note 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 14-3 illustrates the RPR frame.

Fiber Cut

ML-Series RPR

Ring Wrap

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