pdb Module

Edited by

Henning Westerholt

1&1 Internet AG

Pawel Kuzak

1&1 Internet AG

Table of Contents

1. Admin Guide
1. Overview
2. Dependencies
2.1. Kamailio Modules
2.2. External Libraries or Applications
3. Parameters
3.1. timeout (integer)
3.2. server (string)
3.3. ll_info (int)
4. Functions
4.1. pdb_query (string query, string dstavp)
5. RPC Commands
5.1. pdb.status
5.2. pdb.activate
5.3. pdb.deactivate

List of Examples

1.1. Set timeout parameter
1.2. Set server parameter
1.3. Set ll_info parameter
1.4. pdb_query usage
1.5. pdb.status usage
1.6. pdb.activate usage
1.7. pdb.deactivate usage

Chapter 1. Admin Guide

1. Overview

This is a module for fast number portability handling. The client is this module and the server exists in the /utils/pdbt directory. The PDB module and server supports load-balancing and aggressive timeouts. Normally it does not need more than a few ms to query the remote server and return the reply to the configuration script.

The pdb module allows Kamailio to send queries to a list of servers and store the answer in an AVP. The idea is to ask all servers in parallel and use the first answer, that comes back. A timeout for the query can be defined in milliseconds. The querying can be activated and deactivated using FIFO commands.

More about the new communication protocol between this module and pdb_server can be found in utils/pdbt/docs/network_protocol.txt. The current version is 1.

2. Dependencies

2.1. Kamailio Modules

The module depends on the following modules (in other words the listed modules must be loaded before this module):

  • none

2.2. External Libraries or Applications

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

  • The PDB server

3. Parameters

3.1. timeout (integer)

This is the timeout in milliseconds for the pdb_query function.

Default value is 50.

Example 1.1. Set timeout parameter

modparam("pdb", "timeout", 10)

3.2. server (string)

This is the list of servers to be used by the pdb_query function. Queries will be sent in parallel to all servers configured in this list. This parameter is mandatory.

Example 1.2. Set server parameter

modparam("pdb", "server", "localhost:10001,host.name:10001,")

3.3. ll_info (int)

Local log level (per module) for specific INFO messages. It has to be a valid log level value (see xlog() function from xlog module for more details).

Default value is 2.

Example 1.3. Set ll_info parameter

modparam("pdb", "ll_info", 3)

4. Functions

4.1.  pdb_query (string query, string dstavp)

Sends the query string to all configured servers and stores the answer in dstavp. If it takes more than the configured timeout, false is returned. Pseudo-variables or AVPs can be used for the query string. The answer must consist of the null terminated query string followed by a two byte integer value in network byte order. The integer value will be stored in the given AVP.

Example 1.4. pdb_query usage

# query external service for routing information
if (!pdb_query("$rU", "$avp(i:82)"))
  $avp(i:82) = 0; # default routing
cr_route("$avp(i:82)", "$rd", "$rU", "$rU", "call_id");

5. RPC Commands

5.1. pdb.status

Prints the status of the module. This can either be "active" or "deactivated".

Example 1.5. pdb.status usage

kamcmd pdb.status

5.2. pdb.activate

Activates the module. This is the default after loading the module.

Example 1.6. pdb.activate usage

kamcmd pdb.activate

5.3.  pdb.deactivate

Deactivates the module. No more queries are performed until it is activated again. As long as the module is deactivated, the pdb_query function will return -1.

Example 1.7. pdb.deactivate usage

kamcmd pdb.deactivate