Click on the ISDN interfaces button to adjust the global settings for the interfaces used by the ISDN users. An ISDN T interface (external) or even an ISDN TE interface (internal) can be configured. The latter is the case if users of an upstream PBX are to be managed as local users.

- Entry active
 - Activates or deactivates this entry.
 - Name
 - Interface to which the ISDN subscribers are connected.
 - Comment
 - Comment on this entry.
 - ISDN/S0 bus
 - Interfaces for the ISDN users to establish a connection.