User guide

Troubleshooting
109
ISDN Q.931 Cause Values
ISDN link level error messages include the Q.931 cause value. The cause
value displayed is the cause number exactly or the number +128. The
following table is a reference list of the Q.931 cause values.
Cause No. Cause Name
1 Unassigned (unallocated) number
2 No route to specified transit network
3 No route to destination
6 Channel unacceptable
7 Call awarded and being delivered in an established channel
16 Normal call clearing
17 User busy
18 No user responding
19 User alerting, no answer
21 Call rejected
22 Number changed
26 Non-selected user clearing
27 Destination out of order
28 Invalid number format (incomplete number)
29 Facility rejected
30 Response to STATUS INQUIRY
31 Normal, unspecified
34 No circuit/channel available
38 Network out of order
41 Temporary failure
42 Switching equipment congestion
43 Access information discarded
44 Requested circuit/channel not available
47 Resource unavailable, unspecified
49 Quality of service unavailable
50 Requested facility not subscribed
57 Bearer capability not authorized
58 Bearer capability not presently available
63 Service or option not available, unspecified
65 Bearer capability not implemented
66 Channel type not implemented
69 Requested facility not implemented
70 Only restricted digital information bearer capability is
available
79 Service or option not implemented, unspecified
81 Invalid call reference value
82 Identified channel does not exist
83 A suspended call exists, but this call identity does not
84 Call identify in use
85 No call suspended