The value of this object is the ISDN address (the ISDN number and the optional subaddress) of this remote ISDN interface. This is a eleven-bytes octet string with : up to 16 digits in the range 0 to 9 for the ISDN number, an optional separator marking the end of the ISDN number and the beginning of the ISDN subaddress : digit 'A' (':' on the equipment configurator), optional 1 to 4 digits in the range 0 to 9 for the ISDN subaddress, mandatory 'F' digits to pad the value until a total of 22 digits (the equipment configurator does not need this final padding). This value is automatically completed by a selection of digits from the X121 address when this X121 address contains two digits 'A' (':' on the equipment configurator) to make the complete ISDN address. See, in the fcLogicalPorts group, the tables which defines the connections to the ISDN remote interfaces. The default value is 'FF FF FF FF FF FF FF FF FF FF FF' meaning 'empty value' (blank value on the equipment configurator).