5.8 ISDN Primary Rate Interface
5.8.2 Selecting the PRI switch

You have to use the isdn switch-type command to specify the CO PRI switch to which the router connects.

Router(config)#isdn switch-type [switch type]

With Cisco IOS Release 11.3(3)T, this command is also available as a controller command to allow different switches to be supported on different controllers. If configured as a global command, the specified switch type applies to all controllers. The table lists the options for the PRI isdn switch-type command. An incompatible switch-selection configuration can result in failure to make ISDN calls. Reloading the router after changing the switch type is required to make the new configuration effective.