378 APPENDIX B: ISDN COMPLETION CAUSE CODES
0x11 17 User busy The called user cannot accept another call although
compatibility is established.
0x12 18 No user
responding
The user does not respond to call establishment
messages with either an alerting or connect indication
within the allowed time.
0x13 19 User alerting
no answer
The user has provided an alerting indication but no
connect indication within the allowed time.
0x15 21 Call rejected Equipment sending the cause does not wish to accept
this call although it is not busy or incompatible.
0x16 22 Number
changed
The called party number is not assigned.
0x1A 26 Non-selected
user clearing
The user has not been awarded the incoming call.
0x1B 27 Destination out
of order
The destination interface is not operating correctly.
0x1C 28 Invalid number
format
The called party number is invalid, or incomplete.
0x1D 29 Facility rejected The network cannot provide the facility requested.
0x1E 30 Response to
status enquiry
The reason for the STATUS message was the prior
receipt of a STATUS ENQUIRY message.
0x1F 31 Unspecified
cause
Used to report normal events only when no other
cause in the normal class applies.
Resource
unavailable
0x22 34 No circuit
available
An appropriate circuit or channel is not currently
available to handle the call.
0x23 35 Call queued
(AT&T)
The network is not functioning. Immediate redial is
unlikely to be successful.
0x26 38 Network out of
order
The network is not functioning. Immediate redial is
unlikely to be successful.
0x29 41 Temporary
failure
The network is not functioning. Immediate redial is
unlikely to be successful.
0x2A 42 Network
congestion
The switching equipment generating this cause is
experiencing a period of high traffic.
0x2B 43 Access info
discarded
The network could not deliver access information to
the remote user as requested. May include the type of
discarded information (user-to-user information, low
layer or high layer compatibility, or sub-address).
0x2C 44 Requested
channel not
available
Returned when the circuit (or channel) indicated by the
requesting entity cannot be provided by the other side
of the interface.
Table 83 Completion Cause Codes (continued)
Class Grouping Hex Code
Decimal
Code
Description Details
