Enum Module


Table of Contents

1. Admin Guide
1.1. Overview
1.2. Dependencies
1.3. Exported Parameters
1.3.1. domain_suffix (string)
1.3.2. tel_uri_params (string)
1.3.3. i_enum_suffix (string)
1.3.4. isn_suffix (string)
1.3.5. branchlabel (string)
1.3.6. bl_algorithm (string)
1.4. Exported Functions
1.4.1. enum_query([suffix], [service], [number])
1.4.2. i_enum_query([suffix], [service])
1.4.3. isn_query([suffix], [service])
1.4.4. is_from_user_enum([suffix], [service])
2. Contributors
2.1. By Commit Statistics
2.2. By Commit Activity
3. Documentation
3.1. Contributors

List of Tables

2.1. Top contributors by DevScore(1), authored commits(2) and lines added/removed(3)
2.2. Most recently active contributors(1) to this module

List of Examples

1.1. Setting domain_suffix module parameter
1.2. Setting tel_uri_params module parameter
1.3. Setting i_enum_suffix module parameter
1.4. Setting isn_suffix module parameter
1.5. Setting branchlabel module parameter
1.6. Zone file example
1.7. Zone file example
1.8. Setting the bl_algorithm module parameter
1.9. enum_query usage
1.10. isn_query usage
1.11. is_from_user_enum usage

Chapter1.Admin Guide

1.1.Overview

Enum module implements [i_]enum_query functions that make an enum query based on the user part of the current Request-URI. These functions assume 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.. i_enum_query operates in a similar fashion. The only difference is that it adds a label (default "i") to branch off from the default, user-ENUM tree to an infrastructure ENUM tree.

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" or "e2u+type[:subtype][+type[:subtype]...]" (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.

When using enum_query without any parameters, it searches for NAPTRs with service type "e2u+sip" in the default enum tree. When using enum_query with a single parameter, this parameter will be used as enum tree. When using enum_query with two parameters, the functionality depends on the first letter in the second parameter. When the first letter is not a '+' sign, the second parameter will be used to search for NAPTRs with service type "e2u+parameter:sip". When the second parameter starts with a '+' sign, the ENUM lookup also supports compound NAPTRs (e.g. "e2u+voice:sip+video:sip") and searching for multiple service types within one lookup. Multiple service types must be separated by a '+' sign.

Most of the time you want to route based on the RURI. On rare occasions you may wish to route based on something else. The function enum_pv_query mimics the behavior of the enum_query function except the E.164 number in its pseudo variable argument is used for the enum lookup instead of the user part of the RURI. Obviously the user part of the RURI is still used in the NAPTR regexp.

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

In addition to standard ENUM, support for ISN (ITAD Subscriber Numbers) is provided as well. To allow ISN lookups to resolve, a different formatting algorithm is expected by the DNS server. Whereas a ENUM NAPTR record expects a DNS query of the form 9.8.7.6.5.4.3.2.1.suffix, ISN method expects a DNS query of the form 6.5.1212.suffix. That is, a valid ISN number includes a prefix of '56' in the example. The rest of the number is a ITAD (Internet Telephony Administrative Domain) as defined in RFCs 3872 and 2871, and as allocated by the IANA in http://www.iana.org/assignments/trip-parameters. The ITAD is left intact and not refersed as ENUM requires. To learn more about ISN please refer to documents at www.freenum.org.

To complete a ISN lookup on the user part of the Request-URI, isn_query() is used instead of enum_query().

Enum module also implements is_from_user_enum function. This function does an enum lookup on the from user and returns true if found, false otherwise.

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

1.3.1.domain_suffix (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.

Example1.1.Setting domain_suffix module parameter

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.

Note

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

Default value is

Example1.2.Setting tel_uri_params module parameter

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

1.3.3.i_enum_suffix (string)

The domain suffix to be used for i_enum_query() lookups. Can be overridden by a parameter to i_enum_query.

Default value is e164.arpa.

Example1.3.Setting i_enum_suffix module parameter

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

1.3.4.isn_suffix (string)

The domain suffix to be used for isn_query() lookups. Can be overridden by a parameter to isn_query.

Default value is freenum.org.

Example1.4.Setting isn_suffix module parameter

modparam("enum", "isn_suffix", "freenum.org.")

1.3.5.branchlabel (string)

This parameter determines which label i_enum_query() will use to branch off to the infrastructure ENUM tree.

Default value is "i"

Example1.5.Setting branchlabel module parameter

modparam("enum", "branchlabel", "i")

1.3.6.bl_algorithm (string)

This parameter determines which algorithm i_enum_query() will use to select the position in the DNS tree where the infrastructure tree branches off the user ENUM tree.

If set to "cc", i_enum_query() will always inserts the label at the country-code level. Examples: i.1.e164.arpa, i.3.4.e164.arpa, i.2.5.3.e164.arpa

If set to "txt", i_enum_query() will look for a TXT record at [branchlabel].[reverse-country-code].[i_enum_suffix] to indicate after how many digits the label should in inserted.

Example1.6.Zone file example

i.1.e164.arpa.                     IN TXT   "4"
9.9.9.8.7.6.5.i.4.3.2.1.e164.arpa. IN NAPTR "NAPTR content for  +1 234 5678 999"


If set to "ebl", i_enum_query() will look for an EBL (ENUM Branch Label) record at [branchlabel].[reverse-country-code].[i_enum_suffix]. See http://www.ietf.org/internet-drafts/draft-lendl-enum-branch-location-record-00.txt for a description of that record and the meaning of the fields. The RR type for the EBL has not been allocated yet. This version of the code uses 65300. See resolve.h.

Example1.7.Zone file example

i.1.e164.arpa.     TYPE65300  \# 14 (
                              04    ; position
                              01 69 ; separator
                              04 65 31 36 34 04 61 72 70 61 00 ; e164.arpa
;                               )
9.9.9.8.7.6.5.i.4.3.2.1.e164.arpa. IN NAPTR "NAPTR content for  +1 234 5678 999"


Default value is cc

Example1.8.Setting the bl_algorithm module parameter

modparam("enum", "bl_algorithm", "txt")

1.4.Exported Functions

1.4.1. enum_query([suffix], [service], [number])

The function performs an ENUM query on a given E.164 "number" (or R-URI username if "number" is missing) and rewrites the Request-URI with the result of the query. See Overview for more information.

Meaning of the parameters is as follows:

  • suffix (string, optional) - suffix to be appended to the domain name, domain_suffix if missing

  • service (string, optional) - service string to be used in the service field

  • number (string, optional) - a specific E.164 number packed as a string on which the ENUM query is performed (if missing the R-URI username ($rU) will be used).

This function can be used from REQUEST_ROUTE.

Example1.9.enum_query usage

...
# search for "e2u+sip" in freenum.org 
enum_query("freenum.org.", , $avp(number));
...
# search for "e2u+sip" in default tree (configured as parameter)
enum_query();
...
# search for "e2u+voice:sip" in e164.arpa
enum_query("e164.arpa.", "voice");
...
# search for service type "sip" or "voice:sip" or "video:sip"
# note the '+' sign in front of the second parameter
enum_query("e164.arpa.", "+sip+voice:sip+video:sip", $avp(number));
...
# querying for service sip and voice:sip
enum_query("e164.arpa.");
enum_query("e164.arpa.", "voice");
# or use instead
enum_query("e164.arpa.", "+sip+voice:sip");
...

1.4.2. i_enum_query([suffix], [service])

The function performs an enum query and rewrites the Request-URI with the result of the query. This the Infrastructure-ENUM version of enum_query(). The only difference to enum_query() is in the calculation of the FQDN where NAPTR records are looked for.

Meaning of the parameters is as follows:

  • suffix (string, optional) - suffix to be appended to the domain name, i_enum_suffix if missing

  • service (string, optional) - service string to be used in the service field

See ftp://ftp.rfc-editor.org/in-notes/internet-drafts/draft-haberler-carrier-enum-01.txt for the rationale behind this function.

1.4.3. isn_query([suffix], [service])

The function performs a ISN query and rewrites the Request-URI with the result of the query. See Overview for more information.

Meaning of the parameters is as follows:

  • suffix (string, optional) - suffix to be appended to the domain name, isn_suffix if missing

  • service (string, optional) - service string to be used in the service field

This function can be used from REQUEST_ROUTE.

See ftp://www.ietf.org/rfc/rfc3872.txt and ftp://www.ietf.org/rfc/rfc2871.txt for information regarding the ITAD part of the ISN string.

Example1.10.isn_query usage

...
# search for "e2u+sip" in freenum.org 
isn_query("freenum.org.");
...
# search for "e2u+sip" in default tree (configured as parameter)
isn_query();
...
# search for "e2u+voice:sip" in freenum.org
isn_query("freenum.org.", "voice");
...

1.4.4.is_from_user_enum([suffix], [service])

Checks if the user part of from URI is found in an enum lookup. Returns 1 if yes and -1 if not.

Meaning of the parameters is as follows:

  • suffix (string, optional) - suffix to be appended to the domain name, domain_suffix if missing

  • service (string, optional) - service string to be used in the service field

This function can be used from REQUEST_ROUTE.

Example1.11.is_from_user_enum usage

...
if (is_from_user_enum()) {
	....
};
...

Chapter2.Contributors

2.1.By Commit Statistics

Table2.1.Top contributors by DevScore(1), authored commits(2) and lines added/removed(3)

NameDevScoreCommitsLines ++Lines --
1. Juha Heinanen (@juha-h)35141681396
2. Bogdan-Andrei Iancu (@bogdan-iancu)282330296
3. Jan Janak (@janakj)191434575
4. Liviu Chircu (@liviuchircu)1910240375
5. Daniel-Constantin Mierla (@miconda)14124655
6. Vlad Patrascu (@rvlad-patrascu)9347251
7. Razvan Crainea (@razvancrainea)861917
8. Henning Westerholt (@henningw)8314190
9. Greg Fausak7149330
10. Andrei Pelinescu-Onciul53117

All remaining contributors: Dan Pascu (@danpascu), Jiri Kuthan (@jiriatipteldotorg), Klaus Darilion, Konstantin Bokarius, Klaus Darilion, Andreas Granig, Peter Lemenkov (@lemenkov), Edson Gellert Schubert, Dusan Klinec.

(1) DevScore = author_commits + author_lines_added / (project_lines_added / project_commits) + author_lines_deleted / (project_lines_deleted / project_commits)

(2) including any documentation-related commits, excluding merge commits. Regarding imported patches/code, we do our best to count the work on behalf of the proper owner, as per the "fix_authors" and "mod_renames" arrays in opensips/doc/build-contrib.sh. If you identify any patches/commits which do not get properly attributed to you, please submit a pull request which extends "fix_authors" and/or "mod_renames".

(3) ignoring whitespace edits, renamed files and auto-generated files

2.2.By Commit Activity

Table2.2.Most recently active contributors(1) to this module

NameCommit Activity
1. Razvan Crainea (@razvancrainea)Jun 2011 - Sep 2019
2. Vlad Patrascu (@rvlad-patrascu)May 2017 - Sep 2019
3. Liviu Chircu (@liviuchircu)Sep 2012 - Apr 2019
4. Dan Pascu (@danpascu)Apr 2019 - Apr 2019
5. Bogdan-Andrei Iancu (@bogdan-iancu)Sep 2005 - Apr 2019
6. Peter Lemenkov (@lemenkov)Jun 2018 - Jun 2018
7. Dusan KlinecDec 2015 - Dec 2015
8. Juha Heinanen (@juha-h)Jan 2003 - Apr 2008
9. Daniel-Constantin Mierla (@miconda)Oct 2005 - Mar 2008
10. Konstantin BokariusMar 2008 - Mar 2008

All remaining contributors: Edson Gellert Schubert, Henning Westerholt (@henningw), Klaus Darilion, Greg Fausak, Andreas Granig, Klaus Darilion, Andrei Pelinescu-Onciul, Jiri Kuthan (@jiriatipteldotorg), Jan Janak (@janakj).

(1) including any documentation-related commits, excluding merge commits

Chapter3.Documentation

3.1.Contributors

Last edited by: Liviu Chircu (@liviuchircu), Dan Pascu (@danpascu), Peter Lemenkov (@lemenkov), Bogdan-Andrei Iancu (@bogdan-iancu), Razvan Crainea (@razvancrainea), Juha Heinanen (@juha-h), Daniel-Constantin Mierla (@miconda), Konstantin Bokarius, Edson Gellert Schubert, Greg Fausak, Klaus Darilion, Jan Janak (@janakj).

Documentation Copyrights:

Copyright 2002-2003 Juha Heinanen