ALIAS_DB Module

Daniel-Constantin Mierla

   <team@voice-system.ro>

Elena-Ramona Modroiu

   <team@voice-system.ro>

Edited by

Daniel-Constantin Mierla

   <team@voice-system.ro>

   Copyright © 2005-2009 Voice Sistem SRL
     __________________________________________________________

   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. db_url (str)
              1.3.2. user_column (str)
              1.3.3. domain_column (str)
              1.3.4. alias_user_column (str)
              1.3.5. alias_domain_column (str)
              1.3.6. domain_prefix (str)
              1.3.7. append_branches (int)

        1.4. Exported Functions

              1.4.1. alias_db_lookup( table_name [,flags] )
              1.4.2. alias_db_find( table_name , input, output
                      [,flags] )

   2. Frequently Asked Questions

   List of Examples

   1.1. Set db_url parameter
   1.2. Set user_column parameter
   1.3. Set domain_column parameter
   1.4. Set alias_user_column parameter
   1.5. Set alias_domain_column parameter
   1.6. Set domain_prefix parameter
   1.7. Set append_branches parameter
   1.8. alias_db_lookup() usage
   1.9. alias_db_find() usage

Chapter 1. Admin Guide

1.1. Overview

   ALIAS_DB module can be used as an alternative for user aliases
   via usrloc. The main feature is that it does not store all
   adjacent data as for user location and always uses database for
   search (no memory caching).

   Having no memory caching, search speed might decrease but
   provisioning is easier. With very fast databases like MySQL,
   speed penalty can be lowered. Also, search can be performed on
   different tables in the same script.

1.2. Dependencies

1.2.1. OpenSIPS Modules

   The following modules must be loaded before this module:
     * database module (mysql, dbtext, ...).

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. db_url (str)

   Database URL.

   Default value is
   “mysql://opensipsro:opensipsro@localhost/opensips”.

   Example 1.1. Set db_url parameter
...
modparam("alias_db", "db_url", "dbdriver://username:password@dbhost/dbna
me")
...

1.3.2. user_column (str)

   Name of the column storing username.

   Default value is “username”.

   Example 1.2. Set user_column parameter
...
modparam("alias_db", "user_column", "susername")
...

1.3.3. domain_column (str)

   Name of the column storing user's domain.

   Default value is “domain”.

   Example 1.3. Set domain_column parameter
...
modparam("alias_db", "domain_column", "sdomain")
...

1.3.4. alias_user_column (str)

   Name of the column storing alias username.

   Default value is “alias_username”.

   Example 1.4. Set alias_user_column parameter
...
modparam("alias_db", "alias_user_column", "auser")
...

1.3.5. alias_domain_column (str)

   Name of the column storing alias domain.

   Default value is “alias_domain”.

   Example 1.5. Set alias_domain_column parameter
...
modparam("alias_db", "alias_domain_column", "adomain")
...

1.3.6. domain_prefix (str)

   Specifies the prefix to be stripped from the domain in R-URI
   before doing the search.

   Default value is “NULL”.

   Example 1.6. Set domain_prefix parameter
...
modparam("alias_db", "domain_prefix", "sip.")
...

1.3.7. append_branches (int)

   If the alias resolves to many SIP IDs, the first is replacing
   the R-URI, the rest are added as branches.

   Default value is “0” (0 - don't add branches; 1 - add
   branches).

   Example 1.7. Set append_branches parameter
...
modparam("alias_db", "append_branches", 1)
...

1.4. Exported Functions

1.4.1.  alias_db_lookup( table_name [,flags] )

   The function takes the R-URI and search to see whether it is an
   alias or not. If it is an alias for a local user, the R-URI is
   replaced with user's SIP uri.

   The function returns TRUE if R-URI is alias and it was replaced
   by user's SIP uri.

   Meaning of the parameters is as follows:
     * table_name - the name of the table where to search for
       alias. It can include pseudo-variables.
     * flags (optional) - set of flags (char based flags) to
       control the alias lookup process:
          + d - do not use domain URI part in the alias lookup
            query (use only a username-based lookup). By default,
            both username and domain are used.
          + r - do revers alias lookup - lookup for the alias
            mapped to the current URI (URI 2 alias translation);
            normally, the function looks up for the URI mapped to
            the alias (alias 2 URI translation).

   This function can be used from REQUEST_ROUTE, FAILURE_ROUTE.

   Example 1.8. alias_db_lookup() usage
...
alias_db_lookup("dbaliases" , "rd");
alias_db_lookup("dba_$(rU{s.substr,0,1})");
...

1.4.2.  alias_db_find( table_name , input, output [,flags] )

   The function is very similar to alias_db_lookup(), but instead
   of using fixed input (RURI) and output (RURI) is able to get
   the input SIP URI from a pseudo-variable and place the result
   back also in a pseudo-variable.

   The function is useful as the alias lookup does not affect the
   request itself (no RURI changes), can be used in a reply
   context (as it does not work with RURI only) and can be used
   for others URI than the RURI (To URI, From URI, custom URI).

   The function returns TRUE if any alias mapping was found and
   returned.

   Meaning of the parameters is as follows:
     * table_name - the name of the table where to search for
       alias. It can include pseudo-variables.
     * input - any PV (pseudo-variable) carrying the SIP URI that
       needs to be looked up.
     * ouput - PV (AVP or script VAR) where to place the SIP URI
       resulting from the alias lookup.
     * flags (optional) - set of flags (char based flags) to
       control the alias lookup process:
          + d - do not use domain URI part in the alias lookup
            query (use only a username-based lookup). By default,
            both username and domain are used.
          + r - do revers alias lookup - lookup for the alias
            mapped to the current URI (URI 2 alias translation);
            normally, the function looks up for the URI mapped to
            the alias (alias 2 URI translation).

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

   Example 1.9. alias_db_find() usage
...
# do revers alias lookup and find the alias for the FROM URI
alias_db_find("dbaliases" , "$fu", "$avp(from_alias)", "r");
...

Chapter 2. Frequently Asked Questions

   2.1.

       What happened with old use_domain parameter

       The global parameter (affecting the entire module) was replaced
       with a per lookup parameter (affecting only current lookup).
       See the "d" (do not used domain part) flag in the
       db_alias_lookup() and db_alias_find() functions.

   2.2.

       How can I report a bug?

       Please follow the guidelines provided at:
       https://github.com/OpenSIPS/opensips/issues.
