ISDN address
An ISDN address consists of the ISDN telephone number and an optional ISDN subaddress.
The ISDN telephone number has a maximum of 15 digits and consists of the country code(LKZ) and the local network code(ONKz) as well as the subscriber number. The ISDN subaddress has 32 digits and is particularly suitable for connecting local data networks. It can be used to address data stations in a LAN that is connected to ISDN via gateways.
When establishing a connection, at least the destination number must be specified. In addition, the called number can be specified or a called or calling subaddress. On the called side the called and the calling number is displayed. The calling number always contains the area code and for calls from abroad also the country code. The called number is displayed without the area code.