# &adminguide;

## Overview

This module contains methods for IPSec initialisation/deinitialisation related for usage of Kamailio as a Proxy-CSCF.

## Dependencies

### &kamailio; Modules

The Following modules must be loaded before this module:

- Usrloc PCSCF

- TM

### External Libraries or Applications

This modules requires the internal IMS library and libmnl for operating with netlink sockets.

## Parameters

### `ipsec_listen_addr` (string)

IP address which the Proxy-CSCF will use for incoming/outgoing SIP traffic over IPSec.

Default value is empty string (null) - IPv4 listen interface will not be added

#### `ipsec_listen_addr` parameter usage

    ...
    modparam("ims_ipsec_pcscf", "ipsec_listen_addr", "")
    ...

### `ipsec_listen_addr6` (string)

IPv6 address which the Proxy-CSCF will use for incoming/outgoing SIP traffic over IPSec.

Default value is empty string (null) - IPv6 listen interface will not be added

#### `ipsec_listen_addr6` parameter usage

    ...
    modparam("ims_ipsec_pcscf", "ipsec_listen_addr6", "")
    ...

### `ipsec_client_port` (int)

Start port number which will be bound for incoming (server) IPSec traffic.

Default value is 5062.

#### `ipsec_client_port` parameter usage

    ...
    modparam("ims_ipsec_pcscf", "ipsec_client_port", 5062)
    ...

### `ipsec_server_port` (int)

Start port number which will be bound for incoming (server) IPSec traffic.

Default value is 5063.

#### `ipsec_server_port` parameter usage

    ...
    modparam("ims_ipsec_pcscf", "ipsec_server_port", 5063)
    ...

### `ipsec_max_connections` (int)

Maximum IPSec connections for the process. E.g. if ipsec_client_port=5100, ipsec_server_port=6100 and ipsec_max_connections=10, all client ports between 5100 and 5109 and all server ports between 6100 and 6109 will be used for maximum to 10 IPSec connections.

Default value is 2.

#### `ipsec_max_connections` parameter usage

    ...
    modparam("ims_ipsec_pcscf", "ipsec_max_connections", 10)
    ...

### `ipsec_reuse_server_port` (int)

Reuse (1) or not (0) the P-CSCF Server port for Re-registration for one UA. When set to 0 - During Re-registration P-CSCF will distribute new P-CSCF client and P-CSCF server ports. When set to 1 - During Re-registration P-CSCF will reuse the old P-CSCF server port and will distribute a new P-CSCF client port.

Default value is 1.

#### `ipsec_reuse_server_port` parameter usage

    ...
    modparam("ims_ipsec_pcscf", "ipsec_reuse_server_port", 1)
    ...

### `ipsec_spi_id_start` (int)

Each IPSec tunnel has a unique system-wide identifier. This and the following option allows to tune the SPIs used by Kamailio in order to avoid collisions with other IPSec useres. If Kamailio is the only process on the system which uses IPSec, don't bother with this option.

Default value is 100.

#### `ipsec_spi_id_start` parameter usage

    ...
    modparam("ims_ipsec_pcscf", "ipsec_spi_id_start", 100)
    ...

### `ipsec_spi_id_range` (int)

How many SPIs to be allocated for the process. E.g. if ipsec_spi_id_start = 100 and ipsec_spi_id_range = 1000, SPIs between 100 and 1100 will be used.

Default value is 1000.

#### `ipsec_spi_id_range` parameter usage

    ...
    modparam("ims_ipsec_pcscf", "ipsec_spi_id_range", 1000)
    ...

## Functions

### `ipsec_create(domain)`

This function creates IPSec SA and Policy based on the parameters sent in Security-Client header in the REGISTER message. It's called when OK is received. The function also adds Security-Server header to the REGISTER.

Meaning of the parameters is as follows:

- domain - Logical domain within the registrar. If a database is used then this must be name of the table which stores the contacts.

  flags - bitwise flag: 0x01 - if set - delete unused tunnels before every registration. This is an optional parameter, default value - 0.

#### ipsec_create

    ...
    ipsec_create("location");
    # or
    ipsec_create("location", "1");
    ...

### `ipsec_forward(domain, flags)`

The function processes redirects outgoing message via the IPSec tunnel initiated with ipsec_create().

Meaning of the parameters is as follows:

- domain - Logical domain within the registrar. If a database is used then this must be name of the table which stores the contacts.

  flags - bitwise flag: 0x01 - set force socket for request messages. Useful for ipsec and TCP. 0x02 - reverse search for a contact in the memory. Useful when contact alias is disabled. This is an optional parameter, default value - 0.

#### ipsec_forward

    ...
    ipsec_forward("location");
    # or
    ipsec_forward("location", "1");
    ...

### `ipsec_destroy(domain)`

The function destroys IPSec tunnel, created with ipsec_create.

Meaning of the parameters is as follows:

- domain - Logical domain within the registrar. If a database is used then this must be name of the table which stores the contacts.

#### ipsec_destroy

    ...
    ipsec_destroy("location");
    ...