The number of the ISDN partner that is allowed to login
via isdnlogin through the corresponding ISDN Stack.
The wildcards '*', '?', '[', ']', '{', '}' may be used.
See isdnCallRemoteNumber.
The screening indicator of the calling party number (CPN).
The isdnloginAllowScreening field can be used to gauge the
`trustworthiness' of the CPN field (see isdnCallScreening).
Indicators are ordered from highest to lowest as follows:
indicator: CPN assigned: verification:
`network' by network none
`user-verified' by user verification successful
`user' by user none
`user-failed' by user verification failed
Set this field to `dont-care' to accept all calls.
Set this field to `delete' to delete this entry.
Otherwise calls are accepted only if the screening
indicator matches or is higher than the set value.