3.2 ENUM Query Validation
The ENUM application validates the incoming ENUM Query message to verify whether the the message conforms to the Query format. At a minimum, ENUM supports validations for the error conditions shown in the following table to be handled during the validation of ENUM query:
Table 3-3 ENUM Query Validation Errors
| Error Condition | Response |
|---|---|
|
QR (Query/Response flag) Field in ENUM Query Header = 1 |
ENUM Error Response with RCODE=1 (Format Error) |
|
OPCODE other than 0 (Not a standard DNS query) |
ENUM Error Response with RCODE=4 (Not Implemented) |
|
TC (Truncation Flag) in ENUM Query Header = 1 |
ENUM Error Response with RCODE=4 (Not Implemented) |
|
TC (Truncation Flag) in ENUM query header = 0 and query packet size > 512 bytes |
ENUM Error Response with RCODE=4 (Not Implemented) |
|
Z (Reserved Field) in ENUM Query Header = 1 |
ENUM Error Response with RCODE=4 (Not Implemented) |
|
RCODE(Response Code) in ENUM Query Header = 1 |
ENUM Error Response with RCODE=1 (Format Error) |
|
QDCOUNT (Question Count) in ENUM Query Header > 1 |
ENUM Error Response with RCODE=4 (Not Implemented) |
|
ENUM Query Question Section QNAME field root other than e164.arpa |
ENUM Error Response with RCODE=3 (Non-Existent Domain Error) |
|
ENUM Query Question Section QTYPE field other than NAPTR (35), NS (2) or CNAME (5) |
ENUM Error Response with RCODE=4 (Not Implemented) |
|
ENUM Query Question Section QCLASS field other than 1 (Internet) |
ENUM Error Response with RCODE=4 (Not Implemented) |