1.1. Overview

Enum module implements enum_query function that makes an enum query based on the user part of the current Request-URI. The function assumes that the user part consists of an international phone number of the form +decimal-digits, where the number of digits is at least 2 and at most 15. Out of this number enum_query forms a domain name, where the digits are in reverse order and separated by dots followed by domain suffix that by default is "e164.arpa.". For example, if the user part is +35831234567, the domain name will be "7.6.5.4.3.2.1.3.8.5.3.e164.arpa.".

After forming the domain name, enum_query queries DNS for its NAPTR records. From the possible response enum_query chooses those records, whose flags field has string value "u", and whose services field has string value "e2u+[service:]sip" (case is ignored in both cases), and whose regexp field is of the form !pattern!replacement!.

Then enum_query sorts the chosen NAPTR records based on their <order, preference>. After sorting, enum_query replaces the current Request URI by applying regexp of the most preferred NAPTR record its user part and appends to the request new branches by applying regexp of each remaining NAPTR record to the user part of the current Request URI. If a new URI is a tel URI, enum_query appends to it as tel URI parameters the value of tel_uri_params module parameter. Finally, enum_query associates a q value with each new URI based on the <order, preference> of the corresponding NAPTR record.

Enum query returns 1 if the current Request URI was replaced and -1 if not.

Enum module also implements is_from_user_e164 function that checks if the user part of from URI is an E164 number.

1.2. Dependencies

The module depends on the following modules (in the other words the listed modules must be loaded before this module):

• No dependencies.

1.3. Exported Parameters

modparam("enum", "domain_suffix", "e1234.arpa.")

---

1.3.2. tel_uri_params (string)

A string whose contents is appended to each new tel URI in the request as tel URI parameters.

Currently OpenSER does not support tel URIs. This means that at present tel_uri_params is appended as URI parameters to every URI.

Default value is ""

Example 1-2. Setting tel_uri_params module parameter

modparam("enum", "tel_uri_params", ";npdi")

1.4. Exported Functions

...
enum_query("freenum.org.");
...

...
if (is_from_user_e164()) {
    ....
};
...