Specifications

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Cisco MGX 8800/8900 Series Software Configuration Guide
Release 5.1, Part Number OL-6482-01, Rev. A0, January 25, 2005
Chapter 8 Managing PNNI Nodes and PNNI Routing
Managing Connection Grooming
Negotiated Slave Soft Reroute Capability: DISABLE
Soft Reroute Last Cause: N/A. Soft Reroute is not performed yet.
In the example above, the transmit and receive values for CDV and CTD are -1. Also the Max Cost value
is set to -1. The Max Cost of a connection is defined during connection configuration and specifies the
maximum permissible sum of the administrative weight (AW) on each line along that connection.
The default configuration uses the AW metric for connection grooming. However, you can use the
cnfcon command to configure a connection to use maximum cost, CTD, or CDV metrics. If only one of
the metrics is configured, that metric is evaluated. If multiple metrics are configured, the metric with the
highest priority is evaluated. The highest priority is AW, which is selected whenever a maximum cost is
configured. The second highest priority is CTD, and the lowest priority is CDV. Table 8-13 shows how
metrics are chosen based on the connection configuration.
The grooming operation uses both the percentage and absolute thresholds to determine if a prospective
new route is better than the incumbent route. If the new route meets both criteria, the connection is
rerouted. For example, if the incumbent connection cost is 1000, the absolute threshold is 100 and the
percentage reduction is 5, the connection will be rerouted only if the new connection cost is less than or
equal to 900. To calculate the cost reduction based on the absolute threshold, subtract 100 from the
incumbent connection cost of 1000. To calculate the reduction based on the percentage threshold,
multiply the connection cost by 5 percent (1000*5/100 = 50). Because the absolute threshold metric
requires the larger cost reduction in this example, the absolute threshold of 100 is used to determine if
rerouting should take place.
To set the grooming thresholds used for scheduled and manual grooming, enter the cnfrteoptthresh
command as follows:
M8850_LA.7.PXM.a > cnfrteoptthresh <type> [-awcbr <value>] [-awrtvbr <value>]
[-awnrtvbr <value>] [-awubr <value>] [-awabr <value>] [-ctdcbr <value>]
[-ctdrtvbr <value>] [-cdvcbr <value>] [-cdvrtvbr <value>]
Table 8-14 describes the cnfrteoptthresh command parameters.
Table 8-13 Grooming Metric Selection
Connection Configured Metric
Selected
MetricMax. Cost CTD CDV
No No No AW
No No Yes CDV
No Yes No CTD
No Yes Yes CTD
YesNoNoAW
Yes No Yes AW
Yes Yes No AW
Yes Yes Yes AW