Specifications

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Cisco MGX 8850 (PXM45) and MGX 8950 Software Configuration Guide
Release 3, Part Number 78-14788-01 Rev. C0, January 2004
Chapter 6 Managing PNNI Nodes and PNNI Routing
Managing PNNI Route and Link Selection
To configure the route selection method, enter the cnfpnni-routing-policy command as follows:
8850_LA.7.PXM.a > cnfpnni-routing-policy -onDemand firstfit|bestfit
Enter firstfit to select the first route discovered, or enter bestfit to select the optimum route.
To display the route selection method, enter the dsppnni-routing-policy command as follows:
8850_LA.7.PXM.a > dsppnni-routing-policy
SPT epsilon......... 0 Load balance........ random
SPT holddown time... 1 On demand routing... first fit
SPT path holddown time 2 AW Background Table on
CTD Background Table on CDV Background Table on
The parameter labeled On demand routing shows which route selection method is configured.
Configuring the Best-Fit Route Selection Method
When the PNNI controller is configured to choose the best route and it discovers multiple eligible routes,
the load balancing option determines which route to select. The option settings are random and maxbw,
which selects the route with the greatest available bandwidth. Random selection is used to balance the
load.
Note The route selection process is described in the Cisco MGX and SES PNNI Network Planning Guide.
To configure the best-fit route selection method, enter the cnfpnni-routing-policy command as follows:
8850_LA.7.PXM.a > cnfpnni-routing-policy -loadBalance random|maxbw
Enter random to balance route selection, or enter maxbw to select the route with the greatest available
bandwidth.
To display the route selection method, enter the dsppnni-routing-policy command as follows:
8850_LA.7.PXM.a > dsppnni-routing-policy
SPT epsilon......... 0 Load balance........ random
SPT holddown time... 1 On demand routing... first fit
SPT path holddown time 2 AW Background Table on
CTD Background Table on CDV Background Table on
The parameter labeled Load balance shows which best-fit route selection method is configured.
Configuring Preferred Routes
You can specify a route to be preferred for SPVC and SPVP connections. Once a route is specified as a
preferred route, future SPVC connections attempt to route connections via the preferred route before
attempting other routes. A preferred route can be assigned to multiple SPVCs or SPVPs.
Preferred routes can be configured to be a directed or non-directed. A directed route will only attempt a
connection on the preferred route. If the connection cannot route over the preferred route, that
connection will go into a failed state. Anon-directed route will first attempt to route over the preferred
route. If the preferred route is not available, the connection will be attempted over other routes.