$Revision: 1.2 $
$Date: 2004/09/05 16:09:18 $
User's Guide
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.
Dependencies
The module depends on the following modules (in the other words the listed modules
must be loaded before this module):
No dependencies.
Exported Parameters
<varname>domain_suffix</varname> (string)
The domain suffix to be added to the domain name obtained from
the digits of an E164 number. Can be overridden by a parameter to
enum_query.
Default value is e164.arpa.
Setting domain_suffix module parameter
modparam("enum", "domain_suffix", "e1234.arpa.")
<varname>tel_uri_params</varname> (string)
A string whose contents is appended to each new tel URI in the request as tel URI parameters.
Currently SER does not support tel URIs. This means that at present
tel_uri_params is appended as URI parameters to every URI.
Default value is
Setting tel_uri_params module parameter
modparam("enum", "tel_uri_params", ";npdi")
Exported Functions
<function moreinfo="none">enum_query(),enum_query("suffix"), enum_query("suffix",
"service")</function>
The function performs an enum query and rewrites the Request-URI with the result of
the query. See for more information.
Meaning of the parameters is as follows:
suffix - Suffix to be appended to the domain name.
service - Service string to be used in the service
field.
<function moreinfo="none">enum_query</function> usage
...
enum_query("freenum.org.");
...
<function moreinfo="none">is_from_user_e164()</function>
Checks if the user part of from URI an E164 number
of the form +[0-9]{2,15}. Returns 1 if yes and -1 if not.
<function moreinfo="none">is_from_user_e164</function> usage
...
if (is_from_user_e164()) {
....
};
...