ccDetailsPreferredIfIndex 1.3.6.1.4.1.207.8.4.4.4.37.1.1.11

The ifIndex of an ISDN interface on this router which is the preferred ISDN interface on which to make an outgoing call using this call details entry. The ifIndex, if not 0, should reference the ifEntry which contains information about the entire ISDN interface, at the lowest layer. If a channel is not available on this interface, the call can try other interfaces in order to make the call. This object is not used on incoming calls. If the value of this object is set to 0, no interface will be preferred over any other. If the value of this object does not reference the ifEntry for the entire ISDN interface, no interface will be preferred.