UAC Module

Bogdan-Andrei Iancu

Ramona-Elena Modroiu

Edited by

Bogdan-Andrei Iancu

Edited by

Ramona-Elena Modroiu

Revision History
Revision $Revision: 8806 $$Date$

Table of Contents

1. Admin Guide
1.1. Overview
1.2. Dependencies
1.2.1. OpenSIPS Modules
1.2.2. External Libraries or Applications
1.3. Exported Parameters
1.3.1. restore_mode (string)
1.3.2. restore_passwd (string)
1.3.3. rr_from_store_param (string)
1.3.4. rr_to_store_param (string)
1.3.5. force_dialog (int)
1.4. Exported Functions
1.4.1. uac_replace_from(display,uri) uac_replace_to(display,uri)
1.4.2. uac_replace_from(uri) uac_replace_to(uri)
1.4.3. uac_restore_from() uac_restore_to()
1.4.4. uac_auth()
2. Frequently Asked Questions

List of Examples

1.1. Set restore_mode parameter
1.2. Set restore_passwd parameter
1.3. Set rr_from_store_param parameter
1.4. Set rr_to_store_param parameter
1.5. Set force_dialog parameter
1.6. uac_replace_from/uac_replace_to usage
1.7. uac_replace_from/uac_replace_to usage
1.8. uac_restore_from/uac_restore_to usage
1.9. uac_auth usage

Chapter 1. Admin Guide

1.1. Overview

UAC (User Agent Client) module provides some basic UAC functionalities like FROM / TO header manipulation (anonymization) or client authentication.

If the dialog module is loaded and a dialog can be created, then the auto mode can be done more efficiently.

Known limitations in this version:

  • authentication does not support qop auth-int, just qop auth;

  • CSeq not increased during authentication - the response may be rejected.

1.2. Dependencies

1.2.1. OpenSIPS Modules

The following modules must be loaded before this module:

  • TM - Transaction Module.

  • RR - Record-Route Module, but only if restore mode for FROM URI is set to “auto”.

  • UAC_AUTH - UAC Authentication Module.

  • Dialog Module, if “force_dialog” module parameter is enabled, or a dialog is created from the configuration script.

1.2.2. External Libraries or Applications

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

  • None

1.3. Exported Parameters

1.3.1. restore_mode (string)

There are 3 mode of restoring the original headers (FROM/TO) URI:

  • none” - no information about original URI is stored; restoration is not possible.

  • manual” - all following replies will be restored, except for the sequential requests - these must be manually updated based on original URI.

  • auto” - all sequential requests and replies will be automatically updated based on stored original URI.

This parameter is optional, it's default value being “auto”.

Example 1.1. Set restore_mode parameter


1.3.2. restore_passwd (string)

String password to be used to encrypt the RR storing paramter (when replacing the TO/FROM headers). If empty, no encryption will be used.

Default value of this parameter is empty.

Example 1.2. Set restore_passwd parameter


1.3.3. rr_from_store_param (string)

Name of Record-Route header parameter that will be used to store (encoded) the original FROM URI.

This parameter is optional, it's default value being “vsf”.

Example 1.3. Set rr_from_store_param parameter


1.3.4. rr_to_store_param (string)

Name of Record-Route header parameter that will be used to store (encoded) the original TO URI.

This parameter is optional, it's default value being “vst”.

Example 1.4. Set rr_to_store_param parameter


1.3.5. force_dialog (int)

Force create dialog if it is not created from the configuration script.

Default value is no.

Example 1.5. Set force_dialog parameter

modparam("uac", "force_dialog", yes)

1.4. Exported Functions

1.4.1.  uac_replace_from(display,uri) uac_replace_to(display,uri)

Replace in FROM/TO header the display name and the URI part.

display and URI parameters can include pseudo-variables.

IMPORTANT: calling the function more than once per branch will lead to inconsistent changes over the request.Be sure you do the change only ONCE per branch. Note that calling the function from REQUEST ROUTE affects all the branches!, so no other change will be possible in the future. For per branch changes use BRANCH and FAILURE route.

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

Example 1.6. uac_replace_from/uac_replace_to usage

# replace both display and uri
# replace only display and do not touch uri
# remove display and replace uri
# remove display and do not touch uri

1.4.2.  uac_replace_from(uri) uac_replace_to(uri)

Replace in FROM/TO header the URI part without altering the display name.

URI parameter can include pseudo-variables.

This function can be used from REQUEST_ROUTE.

Example 1.7. uac_replace_from/uac_replace_to usage


1.4.3.  uac_restore_from() uac_restore_to()

This function will check if the FROM/TO URI was modified and will use the information stored in header parameter to restore the original FROM/TO URI value.

NOTE - this function should be used only if you configured MANUAL restoring of the headers (see restore_mode param). For AUTO and NONE, there is no need to use this function.

This function can be used from REQUEST_ROUTE.

Example 1.8. uac_restore_from/uac_restore_to usage


1.4.4.  uac_auth()

This function can be called only from failure route and will build the authentication response header and insert it into the request without sending anything. Credentials for buiding the authentication response will be taken from the list of credentials provided by the uac_auth module (static or via AVPs).

This function can be used from FAILURE_ROUTE.

Example 1.9. uac_auth usage


Chapter 2. Frequently Asked Questions



What happened with auth_username_avp, auth_realm_avp and auth_password_avp parameters

Due some restructuring of the UAC auth modules, these parameters were moved into the "uac_auth" module. This module is now responsible for handling all the credentials (static defined or dynamically defined via AVPs). The UAC module will still see the credentials defined via the AVPs.


Where can I find more about OpenSIPS?

Take a look at


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 OpenSIPS 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 .


How can I report a bug?

Please follow the guidelines provided at: