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ATM Switch Router Software Configuration Guide
OL-7396-01
Chapter11 Configuring ATM Routing and PNNI
Advanced PNNI Configuration
The switch applies a single link selection method for a group of parallel links connected to a neighbor
switch. If multiple links within this group are configured with a different link selection method, then the
switch selects a method according to the order of precedence as shown in Table11-2.
The link selection feature allows you to specify one or more links among the parallel links as an alternate
(or backup) link. An alternate link is a link that is used only when all other non-alternate links are either
down or full. Alternate links are not considered part of the parallel link group targeted for link selection.
Calls are always load balanced over multiple parallel alternate links by default.
To configure the PNNI link selection feature, perform these steps, beginning in global configuration
mode:
Examples
The following example shows how to configure link selection on ATMinterface 0/0/0 with a VBR-NRT
service category and transmit-speed-maximize mode:
Switch(config)# interface atm 0/0/0
Switch(config-if)# atm pnni link-selection vbr-nrt transmit-speed-maximize
The following example shows how to configure link selection on ATMinterface 0 /0/0 with a CBR
service category and then designate the link as an alternate:
Switch(config)# interface atm 0/0/0
Switch(config-if)# atm pnni link-selection cbr alternate
Displaying the Link Selection Configuration
To display the ATM PNNI link selection configuration, use the following EXEC command:
1. CBR = constant bit rate
2. VBR-RT = variable bit rate real time
3. VBR-NRT = variable bit rate non-real time
4. ABR = available bit rate
5. UBR = unspecified bit rate
Command Purpose
Step1 Switch(config)# interface atm card/subcard/port
Switch(config-if)#
Specifies an ATM interface and enter interface
configuration mode.
Step2 Switch(config-if)# atm pnni link-selection {cbr |
vbr-rt | vbr-nrt | abr | ubr | all}
{admin-weight-minimize | alternate |
blocking-minimize | load-balance |
transmit-speed-maximize}
Configures ATM PNNI link selection for a
specific link.
Command Purpose
show atm pnni neighbor Displays the ATM PNNI link selection
configuration.