| 1 | UNALLOCATED | Unallocated (unassigned) number |
| 2 | NO_ROUTE_TRANSIT_NET | No route to specified transmit network |
| 3 | NO_ROUTE_DESTINATION | No route to destination |
| 6 | CHANNEL_UNACCEPTABLE | Channel unacceptable |
| 7 | CALL_AWARDED_DELIVERED | Call awarded and being delivered in an established channel |
| 16 | NORMAL_CLEARING | Normal Clearing |
| 17 | USER_BUSY | User busy |
| 18 | NO_USER_RESPONSE | No user responding |
| 19 | NO_ANSWER | User alerting, no answer |
| 20 | SUBSCRIBER_ABSENT | |
| 21 | CALL_REJECTED | Call Rejected |
| 22 | NUMBER_CHANGED | Number changed |
| 27 | DESTINATION_OUT_OF_ORDER | Destination out of order |
| 28 | INVALID_NUMBER_FORMAT | Invalid number format |
| 29 | FACILITY_REJECTED | Facility rejected |
| 30 | RESPONSE_TO_STATUS_ENQUIRY | Response to STATus ENQuiry |
| 31 | NORMAL_UNSPECIFIED | Normal, unspecified |
| 34 | NORMAL_CIRCUIT_CONGESTION | Circuit/channel congestion |
| 38 | NETWORK_OUT_OF_ORDER | Network out of order |
| 41 | NORMAL_TEMPORARY_FAILURE | Temporary failure |
| 42 | SWITCH_CONGESTION | Switching equipment congestion |
| 43 | ACCESS_INFO_DISCARDED | Access information discarded |
| 44 | REQUESTED_CHAN_UNAVAIL | Requested channel not available |
| 45 | PRE_EMPTED | Pre-empted |
| 50 | FACILITY_NOT_SUBSCRIBED | Facility not subscribed |
| 52 | OUTGOING_CALL_BARRED | Outgoing call barred |
| 54 | INCOMING_CALL_BARRED | Incoming call barred |
| 57 | BEARERCAPABILITY_NOTAUTH | Bearer capability not authorized |
| 58 | BEARERCAPABILITY_NOTAVAIL | Bearer capability not available |
| 65 | BEARERCAPABILITY_NOTIMPL | Bearer capability not implemented |
| 66 | CHAN_NOT_IMPLEMENTED | Channel not implemented |
| 69 | FACILITY_NOT_IMPLEMENTED | Facility not implemented |
| 81 | INVALID_CALL_REFERENCE | Invalid call reference value |
| 88 | INCOMPATIBLE_DESTINATION | Incompatible destination |
| 95 | INVALID_MSG_UNSPECIFIED | Invalid message unspecified |
| 96 | MANDATORY_IE_MISSING | Mandatory information element is missing |
| 97 | MESSAGE_TYPE_NONEXIST | Message type nonexist. |
| 98 | WRONG_MESSAGE | Wrong message |
| 99 | IE_NONEXIST | Info. element nonexist or not implemented |
| 100 | INVALID_IE_CONTENTS | Invalid information element contents |
| 101 | WRONG_CALL_STATE | Message not compatible with call state |
| 102 | RECOVERY_ON_TIMER_EXPIRE | Recover on timer expiry |
| 103 | MANDATORY_IE_LENGTH_ERROR | Mandatory IE length error |
| 111 | PROTOCOL_ERROR | Protocol error, unspecified |
| 127 | INTERWORKING | Interworking, unspecified |
| 200 | ANSWERED_ELSEWHERE |