This object specifies the local ISDN number. For outgoing calls, it is used as calling party number, unless it is overwritten by the X.25 routing mechanisms. For incoming calls it is used to assign the incoming call to an interface. The called party number of the incoming ISDN call is matched against the value of this object. Wildcards are allowed in this case. Use care, when IfDirection is set to both. No Wildcards are allowed for outgoing calls.