When a DNS request is unsuccessful, the ANSWER section's status field will indicate one of the following status codes:
| Status | Description |
|---|
| REFUSED | Unauthorized or no coverage |
| SERVFAIL | Misformatted request |
| FORMERR | DNS Query Format Error |
| NXDOMAIN | Domain name does not exist |
| NOTAUTH | The server refused to handle the query (not authenticated) |
When such a response is received, the ANSWER section will contain the following properties:
| Property | Type | Description | Optional |
|---|
err | Integer | The error status code | false |
| Code | Description |
|---|
| 1 | Generic error |
| 2 | Unauthorized |
| 3 | No funds |
| 4 | Query not allowed (coverage) |
| 5 | Misformatted MSISDN |
| 6 | Speed limit throttle error |
| Status | Response Error | Reasons |
|---|
| SERVFAIL | 1 (Generic error) | Generic unhandled error |
| NXDOMAIN | 5 (Misformatted MSISDN) | MSISDN invalid, MSISDN prefix not resolvable |
| NOTAUTH | 2 (Unauthorized) | Inactive account, invalid IP, inactive product |
| FORMERR | 1 (Generic error) | Invalid QCLASS or QTYPE, Unparsable domain |
| REFUSED | 1 (Generic error) | Query routing error |
| REFUSED | 4 (Query not allowed) | No coverage for country, no coverage for network |
| REFUSED | 6 (Speed limit throttle error) | Client exceeded the configured speed limit threshold |
