pdt Module

Elena-Ramona Modroiu

Edited by

Elena-Ramona Modroiu


Table of Contents
1. User's Guide
1.1. Overview
1.2. Dependencies
1.2.1. OpenSER Modules
1.2.2. External Libraries or Applications
1.3. Exported Parameters
1.3.1. db_url (string)
1.3.2. db_table (string)
1.3.3. prefix_column (string)
1.3.4. domain_column (string)
1.3.5. prefix (string)
1.3.6. hsize_2pow (integer)
1.3.7. sync_time (integer)
1.3.8. clean_time (integer)
1.4. Exported Functions
1.4.1. prefix2domain(mode)
1.5. Installation & Running
1.5.1. FIFO Commands
2. Developer's Guide
3. Frequently Asked Questions
List of Examples
1-1. prefix-domain translation
1-2. Set db_url parameter
1-3. Set db_table parameter
1-4. Set prefix_column parameter
1-5. Set domain_column parameter
1-6. Set prefix parameter
1-7. Set hsize_2pow parameter
1-8. Set sync_time parameter
1-9. Set clean_time parameter
1-10. prefix2domain usage

Chapter 1. User's Guide

1.1. Overview

This module translates a numerical prefix into a domain and updates accordingly the request URI.

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.

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

and the result will be:

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

Example 1-1. prefix-domain translation

prefix=123
domain[123]=alpha.org

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 and the MySQL script to create the database needed by PDT are located in './doc/'.

  • Sample shell scripts to manage prefix-domain pairs are also located in './doc/' (pdt_fifo_add.sh, pdt_fifo_delete.sh, pdt_fifo_list.sh).


1.2. Dependencies

1.2.1. OpenSER Modules

The following modules must be loaded before this module:

  • A OpenSER database module (e.g., mysql, dbtext).


1.2.2. External Libraries or Applications

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

  • None.


1.3. Exported Parameters

1.3.1. db_url (string)

SQL URL of database--username, password, host, port and database (ex: mysql://username:password@hostname.com/database)

Default value is "mysql://root@127.0.0.1/pdt".

Example 1-2. Set db_url parameter

...
modparam("pdt", "db_url", "mysql://user:xxx@127.0.0.1/ser")
...

1.3.2. db_table (string)

Table name.

Default value is "prefix_domain".

Example 1-3. Set db_table parameter

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

1.3.3. prefix_column (string)

Name of 'prefix' column.

Default value is "prefix".

Example 1-4. Set prefix_column parameter

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

1.3.4. domain_column (string)

Name of 'domain' column.

Default value is "domain".

Example 1-5. Set domain_column parameter

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

1.3.5. 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 1-6. Set prefix parameter

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

1.3.6. hsize_2pow (integer)

Number of the hash entries = 2^hash_size.

Default value is 4.

Example 1-7. Set hsize_2pow parameter

...
modparam("pdt", "hsize_2pow", 4)
...

1.3.7. sync_time (integer)

Time in seconds to synchronize the cache of each process with the changes made through FIFO. Any prefix-domain change made through FIFO is guaranteed to have efect after this period of time past.

Default value is 600.

Example 1-8. Set sync_time parameter

...
modparam("pdt", "sync_time", 300)
...

1.3.8. clean_time (integer)

Time in seconds to clean the changes inserted via FIFO. The changes will be removed from FIFO diff list only when all OpenSER processes applied these changes.

Default value is 900.

Example 1-9. Set clean_time parameter

...
modparam("pdt", "clean_time", 600)
...

1.4. Exported Functions

1.4.1. prefix2domain(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 "mode" parameter specifies whether to strip or not the prefix from user part. If the parameter is missing or it has the value "0", then the prefix is removed along with the leading prefix. If the value is "1", only the leading prefix is removed. If the values is "2" the user part of the URI is not changed.

This function can be used from REQUEST_ROUTE, FAILURE_ROUTE.

Example 1-10. prefix2domain usage

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

1.5. Installation & Running

Make sure you have created the table needed by this module.


1.5.1. FIFO Commands

The modules uses only the cache to look up domains. If you want to add or delete a new prefix-domain pair you have to use FIFO commands. All changes made via FIFO are applied to database. The database is loaded only at OpenSER start up time.

There are three FIFO commands to use with PDT.

  • pdt_add - add a new prefix-domain pair

  • pdt_delete - remove a prefix-domain pair

  • pdt_list - list the prefixes and the domains

Example shell scripts for these commands are placed in './doc/' (pdt_fifo_add.sh, pdt_fifo_delete.sh, pdt_fifo_list.sh). More about, in the comments before the implementation of the functions, inside the 'pdt.c' file.


Chapter 2. Developer's Guide

The module does not provide any API to use in other OpenSER modules.


Chapter 3. Frequently Asked Questions

3.1. Where can I find more about OpenSER?
3.2. Where can I post a question about this module?
3.3. How can I report a bug?

3.1. Where can I find more about OpenSER?

Take a look at http://openser.org/.

3.2. Where can I post a question about this module?

First at all check if your question was already answered on one of our mailing lists:

E-mails regarding any stable OpenSER release should be sent to and e-mails regarding development versions should be sent to .

If you want to keep the mail private, send it to .

3.3. How can I report a bug?

Please follow the guidelines provided at: http://openser.org/bugs.