Cisco Cisco ONS 15454 SONET Multiservice Provisioning Platform (MSPP) Fehlerbehebungsanleitung
Background Information
The Cisco ML−Series RPR currently performs wrap resiliency, and the wrapping technique is simple. The
ML−Series RPR simply redirects packets on a wrapped ring if the packets reach a failure point. Therefore,
only the nodes adjacent to the failure need to be aware of the issue and initiate the wrap. Wrapping also offers
sub−50−ms resiliency and maintains the same network convergence times, regardless of the network size.
ML−Series RPR simply redirects packets on a wrapped ring if the packets reach a failure point. Therefore,
only the nodes adjacent to the failure need to be aware of the issue and initiate the wrap. Wrapping also offers
sub−50−ms resiliency and maintains the same network convergence times, regardless of the network size.
Figure 1 represents an example for wrapping. The traffic from S3 to S4 traverses two nodes in the normal
condition (see arrow A in Figure 1). The path is S3 > S4. Link failure between S3 and S4 results in a wrap,
and the traffic from S3 to S4 traverses four nodes, S3 > S2 > S1 > S4 (see arrow B in Figure 1).
condition (see arrow A in Figure 1). The path is S3 > S4. Link failure between S3 and S4 results in a wrap,
and the traffic from S3 to S4 traverses four nodes, S3 > S2 > S1 > S4 (see arrow B in Figure 1).
Figure 1 The Cisco ML−Series RPR Wrapping
If the pos trigger defects ber_sd_b3 command is not configured, the ML does not wrap the ring upon signal
degrade, which only occurs upon a Signal Failure (LOS, LOF) condition.
degrade, which only occurs upon a Signal Failure (LOS, LOF) condition.
It is important to note that CTC version 6.2 has a new feature called RPR Keepalive. RPR Keepalive wraps
the ring if a signal degrade condition plus other conditions, such as a possible hardware failure, occur. If you
can upgrade the nodes to the 6.2 version, it is recommended that you use the RPR Keepalive feature.
the ring if a signal degrade condition plus other conditions, such as a possible hardware failure, occur. If you
can upgrade the nodes to the 6.2 version, it is recommended that you use the RPR Keepalive feature.
For more information, refer to RPR Keep Alive section of Configuring Resilient Packet Ring.
Problem
The Cisco ML−Series RPR wraps only when a signal failure alarm occurs due to cut fiber. In case of a span
with signal degrade, the RPR drops packets. The show controller pos X command presents an increase in
ber_sd_b3, BIP(B3) errors and results in input CRCs and runts. In the show controller pos X command, X
can be 0 or 1.
with signal degrade, the RPR drops packets. The show controller pos X command presents an increase in
ber_sd_b3, BIP(B3) errors and results in input CRCs and runts. In the show controller pos X command, X
can be 0 or 1.