ENUM interface

ENUM stands for Electronic Numbering Mapping. With it, you can translate telephone numbers in E.164 format into a format that can be used in Internet communications.

The first instance of each term is linked to the definition on our Sinch Support Community.

ENUM protocol

The background process for translating an MSISDN into ENUM format is to:

1. Remove all non-digit characters.
2. Add dots between each digit.
3. Reverse the order of the digits.
4. Add the domain e164.arpa to the end.

For example, an MSISDN in E.164 format would be input as +447786852522. Using ENUM, it would translate to: 2.2.5.2.5.8.6.8.7.7.4.4.e164.arpa.

Parameters

The parameters used in addition to IP address and port number are:

How to connect

Please find the IP address and port number for our ENUM Lookup Server in the table below. The only identifier needed to connect is the IP address you connect from.

Query specification

Question

The question has the format <IP-address>, <MSISDN-in-ENUM-Format>, and e164.arpa IN NAPTR.

An example of a request for an MSISDN of +13392986156 would be:

93.158.78.4 6.5.1.6.8.9.2.9.3.3.1.e164.arpa IN NAPTR

Answer

The answer section will contain a NAPTR record with the MSISDN queried in ENUM format together with the MCC and MNC for the MSISDN queried.

As an example, the answer section to the question above looks like this:

6.5.1.6.8.9.2.9.3.3.1.e164.arpa. 3 IN NAPTR 10 50 “u” “E2U+pstn:tel” “!^(.*)$!tel:\\\\1\\\;mcc=310\\\;mnc=012!”

Examples

Below you will find full examples of queries using the “dig” command.

Successful query

A successful query returns a NAPTR record containing the queried MSISDN in ENUM format as well as MCC and MNC for the MSISDN in the answer section.

dig @93.158.78.4 6.5.1.6.8.9.2.9.3.3.1.e164.arpa IN NAPTR

; < <>> DiG 9.8.3-P1 < <>> @93.158.78.4 6.5.1.6.8.9.2.9.3.3.1.e164.arpa IN NAPTR
;; ->>HEADER< <- opcode: QUERY, status: NOERROR, id: 9512
;; flags: qr; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;6.5.1.6.8.9.2.9.3.3.1.e164.arpa. IN NAPTR
;; ANSWER SECTION:
6.5.1.6.8.9.2.9.3.3.1.e164.arpa. 3 IN NAPTR 10 50 “u” “E2U+pstn:tel”
“!^(.*)$!tel:\\\\1\\\;mcc=310\\\;mnc=012!” .
;; Query time: 206 msec

Unsuccessful query

The answer to an unsuccessful query won't contain any answer section.

No NAPTR record is return and the response code will be received in the status field.

dig @93.158.78.4 6.5.1.6.8.9.2.9.3.3.1.e164.arpa IN NAPTR

; < <>> DiG 9.8.3-P1 < <>> @93.158.78.4 6.5.1.6.8.9.2.9.3.3.1.e164.arpa IN NAPTR
;; ->>HEADER< <- opcode: QUERY, status: SERVFAIL, id: 9512 ;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;6.5.1.6.8.9.2.9.3.3.1.e164.arpa. IN NAPTR ;; Query time: 202 msec

Response codes

The list below specifies the response codes that can be returned: