Appendix C – ISDN Cause Numbers
C-2
FlexSet 120S/280S User Guide
Cause #
CODE MEANING
ACTION
18
no user responding
call later
19
no answer from user (user alerted)
call later
21
call rejected
call later
22
number changed
check number and call again*
23
reverse charging rejected
24
call suspended
25
call resumed
26
non-selecting user clearing
27
destination out of order
call later
28
invalid format (address incomplete)
check number and call again*
29
facility rejected
notify system manager
30
response to status inquiry
31
normal unspecified
no action**
33
circuit out of order
34
no circuit/ channel available
call later*
35
destination unattainable
∗
If the message returns frequently notify system manager