ISDN Switch-type

In order for any ISDN lines to establish Layer-1 connectivity the switch-type has to be defined correctly.

The switch-type is very much country dependant so it’s also important to memorize the switch-type that applies to where you do most of your installations.

If Layer-1 is showing ‘Deactivated’ when using the show isdn status command, only 3 things can be the source of the problem.

  1. isdn switch-type has not been set, or has not been set correctly (The most common problem)
  2. There is a problem with the PSTN (call your telephony service provider)
  3. Cable problems
  4. Physical port failure on the Router.

In order to configure the switch-type you can enter the command

Isdn switch-type {switch-type}

This can be done either in global configuration mode, or on the interface depending on the router and IOS version.

Below are all the switch-type options available 



basic-1tr6 German 1TR6 ISDN switches
basic-5ess AT&T basic rate switches
basic-dms100 NT DMS-100 basic rate switches
basic-net3 NET3 ISDN and Euro-ISDN switches (UK and others), also called E-DSS1 or DSS1
basic-ni National ISDN-1 switches
basic-nwnet3 Norway Net3 switches
basic-nznet3 New Zealand Net3 switches
basic-ts013 Australian TS013 switches
none No switch defined
ntt Japanese NTT ISDN switches (ISDN BRI only)
primary-4ess AT&T 4ESS switch type for the U.S. (ISDN PRI only)
primary-5ess AT&T 5ESS switch type for the U.S. (ISDN PRI only)
primary-dms100 NT DMS-100 switch type for the U.S. (ISDN PRI only)
primary-net5 NET5 ISDN PRI switches (Europe)
primary-ntt INS-Net 1500 for Japan (ISDN PRI only)
primary-ts014 Australian TS014 switches (ISDN PRI only)
vn2 French VN2 ISDN switches (ISDN BRI only)
vn3 French VN3 ISDN switches (ISDN BRI only)
vn4 French VN4 ISDN switches (ISDN BRI only)





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