About the Number Lookup ENUM API

The Number Lookup ENUM API reference contains details about available API parameters and how to interpret incoming responses. We divide the information into the following sections:

  • Number Lookup ENUM API Interface – Review details about how to use the ENUM API interface. Includes what request and response parameters are available.
  • ENUM API Codes – Look up detailed status code information. This section provides details about GSM status codes. These occur when a number is on a 2G network. Details about regular ENUM API status codes are also available.

Number Lookup ENUM API Interface

The Number Lookup API lets you query for details about a phone number. You use the dig command to reach Mitto’s ENUM API. The dig command is a tool used to query DNS nameservers for information about host addresses, mail exchanges, nameservers, and related information. It runs from the command line. If you are not familiar with ENUM APIs, Mitto recommends using the HTTP API instead.

Request Parameters

Primary Interface IP
Port 5353
Secondary Interface IP
Port 5353

Use one of these interfaces with the following base zone: e164.arpa

The complete lookup ENUM command is built as follows:
[Reverse MSISDN number, no special characters, separated by dots].e164.arpa

Example for the number +491725551234 is:

Complete comamand:
dig @ -p 5353 IN NAPTR

Response Parameters

Parameter Data Type Description
sip string The MSISDN added with a ‘+’ sign as preamble
mnc string Mobile Network Code. The length of the MNC can be two or three digits.
mcc string Mobile Country Code. The length of the MCC can be three digits only.
cost decimal The cost of the lookup request.
ported boolean Provides information on the mobile number portability status of the MSISDN (‘0’ not ported, ‘1’ ported)
omnc string If the number was ported, this provides the MNC the MSISDN originally belonged to.
roaming boolean Provides details about the roaming status of the MSISDN (‘0’ in the home network, ‘1’ in roaming)
rmcc string If the MSISDN is roaming, it provides the MCC where the line is at the moment of the request.
MSC string Provides the Global Title of the Mobile Switching Center (the serving network node).
IMSI string Provides the International Mobile Subscriber Identity. This field uniquely identifies the user of a mobile network.
absent boolean Informs you of the status of the user at the time of the lookup request (‘0’ subscriber available, ‘1’ subscriber absent).
gsmcode number Returns the GSM error code giving detailed information.
err string Provides the specific error to a request fault


ENUM Codes

ENUM Code Description Reason
REFUSED Unauthorized IP not registered. ENUM not activated.
SERVFAIL Wrong formatted request Missing parameter(s)

ENUM API Status Codes

Status Code Description Reason
0 Success The lookup was successfully executed.
1 Unknown Error A generic error occurred
2 Unauthorized Missing or invalid credentials
3 Insufficient funds Refused due to insufficient funds
4 Not allowed Lookup type not allowed
5 Invalid MSISDN Not properly formatted MSISDN
6 MSISDN not mobile The number doesn’t belong to a mobile carrier

GSM Status Codes

GSM Error Code Description
0 No error
1 Unknown subscriber
2 Unknown subscriber – NR changed
5 Unidentified subscriber
6 Absent subscriber for SM
7 Unknown equipment
8 Roaming not allowed
9 Illegal subscriber
10 Bearer service not provisioned
11 Teleservice not provisioned
12 Illegal equipment
13 Call barred
21 Facility not supported
27 Absent subscriber
28 Incompatible MS terminal error
31 Subscriber busy for SMS MT
32 Equipment failure
33 MS memory capacity exceeded
34 GSM system failure
35 GSM Data Error – data missing
36 GSM Data Error
45 Subscriber busy
100/101 Internal equipment error
103/104/105 Unspecified GSM error
150/151 Request timeout