The module looks up at the R-URI part of a message and if the user part begins with an established prefix it will update the URI. Updating the uri consists of: remove the prefix from the user part of the uri and keep the rest as the user part of the new uri. The host and port are changed with the domain matched for the leading prefix and the domain in From URI.

<prefix><userid><:password>@<mydomain.com> ...

and the result will be:

<userid><:password>@<domain[:port]>...

Example 1.1. prefix-domain translation

prefix=123, domain(FROM)=siphub.org

entry in database:
 sdomain=siphub.org
    domain[123]=alpha.org
    domain[124]=beta.org
    domain[125]=gamma.org
	
The RURI will be updated in the following way"
sip:12391001@mydomain.com  => sip:91001@alpha.org

The prefix could be prefixed by other digits. These digits will not be used to look up the domain (the classic example, 00 used for international calls, then follows the country prefix). For more information on this, see 'prefix' parameter.

A sample config file is located in './doc/'.
MySQL script to create the database needed by PDT is located in '../../scripts/mysql/pdt-create.sql'

The database is loaded by Kamailio only at start up time and only cache is used to lookup domains. Check the MI Functions for adding/deleting prefix-domain pairs or reloading from database at runtime.
Sample shell scripts to manage prefix-domain pairs are also located in './doc/' (pdt_fifo_list.sh).

2. Dependencies

2.1. Kamailio Modules

The following modules must be loaded before this module:

A Kamailio database module (e.g., mysql, dbtext).

2.2. External Libraries or Applications

The following libraries or applications must be installed before running Kamailio with this module loaded:

None.

3. Parameters

3.1. `db_url` (string)

URL of the database table to be used.

Default value is “mysql://openser:openserrw@localhost/openser”.

Example 1.2. Set db_url parameter

...
modparam("pdt", "db_url", "dbdriver://username:password@dbhost/dbname")
...

3.2. `db_table` (string)

Table name.

Default value is “pdt”.

Example 1.3. Set db_table parameter

...
modparam("pdt", "db_table", "pdt")
...

3.3. `sdomain_column` (string)

Name of 'sdomain' column.

Default value is “sdomain”.

Example 1.4. Set sdomain_column parameter

...
modparam("pdt", "domain_column", "source_domain")
...

3.4. `prefix_column` (string)

Name of 'prefix' column.

Default value is “prefix”.

Example 1.5. Set prefix_column parameter

...
modparam("pdt", "prefix_column", "prefix")
...

3.5. `domain_column` (string)

Name of 'domain' column.

Default value is “domain”.

Example 1.6. Set domain_column parameter

...
modparam("pdt", "domain_column", "hostname")
...

3.6. `prefix` (string)

Default leading prefix who denotes what URI needs to be translated - if it is NULL the module will not check the R-URI against it and the PDT prefix is considered starting from the first digit. Otherwise, the module will check first if the R-URI starts with it and will skip it to look up the domain.

Default value is NULL.

Example 1.7. Set prefix parameter

...
modparam("pdt", "prefix", "00")
...

3.7. `fetch_rows` (integer)

Number of rows to be loaded in one step from database.

Default value is 1000.

Example 1.8. Set fetch_rows parameter

...
modparam("pdt", "fetch_rows", 4000)
...

3.8. `char_list` (string)

The list with characters allowed in prefix.

Default value is “0123456789”.

Example 1.9. Set char_list parameter

...
modparam("pdt", "char_list", "0123456789*+")
...

3.9. `check_domain` (integer)

Module will check if destination domain is duplicated for same source domain (1 - check; 0 - don't check).

Default value is 1.

Example 1.10. Set check_domain parameter

...
modparam("pdt", "check_domain", 0)
...

4. Functions

4.1. `prefix2domain(rewrite_mode, multidomain_mode)`

Build a new URI if it is necessary. Returns 1 when the translation was made or there was nothing to translate (user part of the URI is empty, it does not match the prefix parameter or there is no domain associated with a possible prefix from user part). Returns -1 in error cases.

The translation is done based on lookup up for a entry in the database where the sdomain equals the domain in FROM uri, and the prefix matches the beginning of the user part of the RURI. If such an entry is found, then the domain in RURI is updated with the domain of this entry (sdomain, prefix, domain).

There is also the possibility to have the translation of URI regardless of source domain. This can be achieved inserting in the database entries where sdomain has the value "*".

The “rewrite_mode” parameter specifies whether to strip or not the prefix from user part. The possible values are:

0: the prefix is removed along with the leading prefix.
1: only the leading prefix is removed.
2: the user part of the URI is not changed.
$PV : any PV holding one of the above values.

The “multidomain_mode” parameter specifies the kind of multidomain support to use. The possible values are:

0 : Translation of URI regardless of source domain.
1 : Translation of URI using as source domain the domain in From-URI.
2 : Translation of URI using as source domain the domain in From-URI. In case there is no entry for the required sdomain, it tries the translation using "*" as sdomain.
$PV : any PV holding one of the above values.

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE.

Example 1.11. prefix2domain usage

...
prefix2domain("2", "2");
...
$var(a) = 1;
prefix2domain("$var(a)", "2");
...

4.2. `prefix2domain(rewrite_mode)`

The same as prefix2domain(rewrite_mode, "0"), that is without multidomain support, translation of URI being done regardless of the source domain.

...
prefix2domain("2");
...

4.3. `prefix2domain()`

The same as prefix2domain("0", "0").

...
prefix2domain();
...

4.4. `pd_translate(sdomain, rewrite_mode)`

Translate R-URI based on source domain and longest prefix matching. Returns 1 when the translation was made or there was nothing to translate. Returns -1 in error cases.

The translation is done based on lookup up for an entry in the database where the sdomain parameter equals the sdomain in database table.

The “sdomain” parameter specifies the source domain to be used to match the longest prefix. Can be a static string or dynamic parameter with variables inside.

The “rewrite_mode” parameter specifies whether to strip or not the prefix from user part. The possible values are:

0: the prefix is removed along with the leading prefix.
1: only the leading prefix is removed.
2: the user part of the URI is not changed.
$PV : any PV holding one of the above values.

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE or BRANCH_ROUTE.

Example 1.12. pd_translate usage

...
pd_translate("$fd", "2");
...
pd_translate("*", "$var(a)");
...

5. MI Commands

The database is loaded by Kamailio at start up time. The module uses only the cache to look up domains. If you want to add or delete a new prefix-domain pair at runtime you have to use MI FIFO commands. All changes made via these commands are applied to database and the cache is updated correspondingly.

5.1. `pdt_list`

Produces a listing of the entries prefixes/domains/sdomains.

Name: pdt_list

Parameters:

_sdomain_ : a source domain value.
_prefix_ : a prefix value
_domain_: a domain value

"." (dot) means NULL value

The comparison operation is 'START WITH' -- if domain is 'a' then all domains starting with 'a' are listed.

MI FIFO Command Format:

		:pdt_list:_reply_fifo_file_
		_sdomain_
		_prefix_
		_domain_
		_empty_line_

Examples:

“pdt_list siph 2 .” : Lists the entries where sdomain is starting with 'siph', prefix is starting with '2' and domain is anything
“pdt_list siph 2” : Lists the entries where sdomain is starting with 'siph', prefix is starting with '2' and domain is anything
“pdt_list . 2 open” : Lists the entries where sdomain is anything, prefix starts with '2' and domain starts with 'open'.

5.2. `pdt_reload`

Reload all sdomain-prefix-domain records from database.

Name: pdt_reload

Parameters:

none

MI FIFO Command Format:

		:pdt_reload:_reply_fifo_file_
		_empty_line_

6. Installation and Running

Example shell scripts for MI FIFO commands are placed in './doc/' (pdt_fifo_add.sh, pdt_fifo_delete.sh, pdt_fifo_list.sh).

pdt Module

Elena-Ramona Modroiu

Edited by

Elena-Ramona Modroiu

Chapter 1. Admin Guide

1. Overview

2. Dependencies

2.1. Kamailio Modules

2.2. External Libraries or Applications

3. Parameters

3.1. db_url (string)

3.2. db_table (string)

3.3. sdomain_column (string)

3.4. prefix_column (string)

3.5. domain_column (string)

3.6. prefix (string)

3.7. fetch_rows (integer)

3.8. char_list (string)

3.9. check_domain (integer)