IMS Usrloc PCSCF Module

Jason Penton

Smile Communications

Edited by

Richard Good

Smile Communications

Edited by

Carsten Bock

ng-voice GmbH

Table of Contents

1. Admin Guide
1. Overview
2. Dependencies
2.1. Kamailio Modules
2.2. External Libraries or Applications
3. Parameters
3.1. hash_size (int)
3.2. timer_interval (int)
3.3. db_url (int)
3.4. db_mode (int)
3.5. match_contact_host_port (int)
4. RPC Commands
4.1. ulpcscf.status
5. Statistics
5.1. registered contacts
5.2. impus
5.3. expired contacts
2. Frequently Asked Questions

List of Examples

1.1. Set hash_size parameter
1.2. Set timer_interval parameter
1.3. Set db_url parameter
1.4. Set db_mode parameter
1.5. Set match_contact_host_port parameter

Chapter 1. Admin Guide

1. Overview

This module serves as a storage engine for PCSCF contacts, much like the standard Kamailio module, usrloc, is a storage engine for standard SIP contacts. The concept of a contact in IMS, PCSCF specifically, is very different to that of std. SIP and as a result we have built this new module. Alot of the design has been borrowed from the std. usrloc module. For example. An IMS contact, in PCSCF, needs things like:

  • Diameter Rx session for signalling bearer status. i.e. this is effectively QoS from the network to make sure the signalling link can be 'trusted'

  • IPSEC Security Assocation for secure signalling between UE and PCSCF (first point of contact)

  • IMPU, each contact can have a number of associated public identities (IMPU).

2. Dependencies

2.1. Kamailio Modules

The following 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:

  • None.

3. Parameters

3.1. hash_size (int)

The number of entries of the hash table used by to store the contact records is 2^hash_size. For hash_size=4, the number of entries of the hash table is 16.

Default value is 9.

Example 1.1. Set hash_size parameter

modparam("ims_usrloc_pcscf", "hash_size", 10)

3.2. timer_interval (int)

Number of seconds between two timer runs. The module uses timer to delete expired contacts.

Default value is 60.

Example 1.2. Set timer_interval parameter

modparam("ims_usrloc_pcscf", "timer_interval", 30)

3.3. db_url (int)

Database URL

Default value is "mysql://kamailio:kamailiorw@localhost/kamailio".

Example 1.3. Set db_url parameter

modparam("ims_usrloc_pcscf", "db_url",

3.4. db_mode (int)

This is the database mode to be used for the PCSCF usrloc data persistent storage. Currently this module supports the Write-Through scheme only.

  • 0 - This disables DB mode. Only memory will be used for usrloc and data will not survive a restart.

  • 1 - Write-Through Scheme. All changes to usrloc are immediately refelcted in the database. This is slow but very reliable. This mode will ensure that no registration data is lost as a result of a restart or crash.

Default value is 0.

Example 1.4. Set db_mode parameter

modparam("ims_usrloc_pcscf", "db_mode", 1)

3.5. match_contact_host_port (int)

If set to 1 (default), the contact is matched using only host and port in the contact URI.

  • 0 - When matching contact do full contact match procedure.

  • 1 - When matching contact compare only host and port of the contact URI.

Default value is 1.

Example 1.5. Set match_contact_host_port parameter

modparam("ims_usrloc_pcscf", "match_contact_host_port", 0)

4. RPC Commands

exported RPC commands.

4.1. ulpcscf.status

Status of pcscf_usrloc, AORs, max slots, etc.

5. Statistics

Exported statistics are listed in the next sections.

5.1. registered contacts

Number of AOR contacts in registered state - cannot be reset.

5.2. impus

Number of IMPUs - cannot be reset.

5.3. expired contacts

Number of expired contacts - can be reset.

Chapter 2. Frequently Asked Questions

2.1. Where can I find more about Kamailio?
2.2. Where can I post a question about this module?
2.3. How can I report a bug?


Where can I find more about Kamailio?

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 Kamailio 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: