isdn Directory Number

1.3.6.1.2.1.10.20.1.5.1.1.2

A Directory Number. Directory Numbers are used to identify incoming calls on the signaling channel given in isdnDirectorySigIndex. The format of this information largely depends on the type of switch or PBX the device is connected to. Therefore, the detailed format of this information is not specified and is implementation dependent. If possible, the agent should implement this information using the E.164 number format. In this case, the number must start with '+'. Otherwise, IA5 number digits must be used.