cnxcc Module

Carlos Ruiz Díaz

   ConexionGroup S.A.

   Copyright © 2013 Carlos Ruiz Díaz, carlos.ruizdiaz@gmail.com

   Copyright © 2014 Carlos Ruiz Díaz, carlos@latamvoices.com
     __________________________________________________________________

   Table of Contents

   1. Admin Guide

        1. Overview
        2. Dependencies

              2.1. Modules
              2.2. Libraries

        3. Parameters

              3.1. redis (integer)
              3.2. credit_check_period (integer)

        4. Functions

              4.1. cnxcc_set_max_credit()
              4.2. cnxcc_set_max_time()
              4.3. cnxcc_update_max_time()
              4.4. cnxcc_set_max_channel()
              4.5. cnxcc_terminate_all()

        5. Exported RPC Commands

              5.1. cnxcc.active_clients
              5.2. cnxcc.check_client
              5.3. cnxcc.kill_call

        6. Events
        7. Web Interface
        8. Sample

   List of Examples

   1.1. dlg_flag
   1.2. credit_check_period
   1.3. cnxcc_set_max_credit()
   1.4. cnxcc_set_max_time()
   1.5. cnxcc_update_max_time()
   1.6. cnxcc_set_max_channels()
   1.7. cnxcc_set_max_time()
   1.8. kamailio-cnxcc.cfg

Chapter 1. Admin Guide

   Table of Contents

   1. Overview
   2. Dependencies

        2.1. Modules
        2.2. Libraries

   3. Parameters

        3.1. redis (integer)
        3.2. credit_check_period (integer)

   4. Functions

        4.1. cnxcc_set_max_credit()
        4.2. cnxcc_set_max_time()
        4.3. cnxcc_update_max_time()
        4.4. cnxcc_set_max_channel()
        4.5. cnxcc_terminate_all()

   5. Exported RPC Commands

        5.1. cnxcc.active_clients
        5.2. cnxcc.check_client
        5.3. cnxcc.kill_call

   6. Events
   7. Web Interface
   8. Sample

1. Overview

   This module was designed to act as a mechanism to limit call duration
   based on credit information parameters. After getting the credit
   information of the call being set up, you can instruct the module to
   start monitoring the consumed credit to shutdown a single call or a
   group of calls in case of credit exhaustion.

   Every call is associated to an unique client/customer identifier. If a
   credit event occurs, all calls hooked to this identifier are
   automatically shutdown.

   Cnxcc is dialog-aware so there's no need to explicitly
   allocate/deallocate the monitoring. Only a single function call inside
   the script is needed upon reception of the INVITE.

   The credit discount rate is proportional to the number of calls grouped
   inside an identifier. Once the setup of the first call is done, the
   information remains while the call is active. If the customer starts a
   new call with the same routing criteria, it will land in the same
   monitoring bag and it will consume the same pool of credit in rates
   that are equal to the cost per second of both calls.

   If your accounting program does not maintain the state of the call in
   real time, this module can provide you with that ability.

   Cnxcc can also provide more common means of monitoring, i.e., by time
   limit or by maximum simultaneous calls.

2. Dependencies

   2.1. Modules
   2.2. Libraries

2.1. Modules

   The following module must be loaded before this module:
     * dialog

2.2. Libraries

   The following module must be loaded before this module:
     * hiredis-devel >= 0.11.0
     * libevent-devel >= 2.0.18-2

3. Parameters

   3.1. redis (integer)
   3.2. credit_check_period (integer)

3.1.  redis (integer)

   Redis datasource connection information

   Example 1.1. dlg_flag
...
modparam("cnxcc", "redis", "addr=127.0.0.1;port=6379;db=1")
...

3.2. credit_check_period (integer)

   Indicates how often the credit checking function should be called. It
   is directly related to the precison of the module. The maximum
   precision is 1, which means that every call is checked every one
   second.

   Values greater than 1 leads to precision lost but less CPU consumption.

   Example 1.2. credit_check_period
...
modparam("cnxcc", "credit_check_period", 1)
...

4. Functions

   4.1. cnxcc_set_max_credit()
   4.2. cnxcc_set_max_time()
   4.3. cnxcc_update_max_time()
   4.4. cnxcc_set_max_channel()
   4.5. cnxcc_terminate_all()

4.1.  cnxcc_set_max_credit()

   Specifies the initial pulse, final pulse, max credit and cost per
   second of a call. The discount is calculated in pulses (30/6, 1/1, etc)
   and sustracted from the pool of credit.

   Return code:
     * 1 - successful
     * -1 - failed, error logged
     * -2 - failed, credit value is less than initial pulse value

   Example 1.3. cnxcc_set_max_credit()
...
$var(customer) = "john-doe-123-premium";
$var(credit) = "100";
$var(cps)   = "2.00";         # cost per second
$var(initial_p)   = "030";    # intial pulse
$var(final_p)   = "006";      # final pulse

cnxcc_set_max_credit("$var(customer)", "$var(credit)", "$var(cps)", "$var(initia
l_p)", "$var(final_p)");
...

4.2.  cnxcc_set_max_time()

   Specifies the amount of time the call should last at most.

   Return code:
     * 1 - successful
     * -1 - failed, error logged

   Example 1.4. cnxcc_set_max_time()
...
$var(customer) = "john-doe-123-basic";
$var(max_time) = 120;

cnxcc_set_max_time("$var(customer)", "$var(max_time)");
...

4.3.  cnxcc_update_max_time()

   Updates max-time of an established and monitored call. This can be used
   to grant minimum values and to update them every short periods on time
   as a mean to prevent frauds and/or to mimic requested/granted units of
   time of Credit Control Application behavior.

   Return code:
     * 1 - successful
     * -1 - failed, error logged

   Example 1.5. cnxcc_update_max_time()
...
        $var(update_time)  = 5;
        $var(client)       = "john-doe-123-basic";

        if (!cnxcc_update_max_time("$var(client)",
                                  "$var(update_time)")) {
                xlog("Error updating max-time");
                return;
        }

...

4.4.  cnxcc_set_max_channel()

   Specifies a limit for the number of simultaneous calls

   Return code:
     * 1 - successful
     * -1 - failed, error logged
     * -2 - failed, calls established plus calls being established result
       in more than the limit you specified
     * -3 - failed, number of calls established is more than the limit you
       specified

   Example 1.6. cnxcc_set_max_channels()
...
$var(customer)  = "john-doe-123-basic";
$var(max_chan)  = 2;
$var(retcode)   = cnxcc_set_max_channels("$var(customer)", "$var(max_chan)");

if ($var(retcode) == -1) {
        xlog("Error setting up credit control");
        return;
}

if ($var(retcode) < -1) {
        xlog("Too many channels for customer");
        sl_send_reply(403, "Forbidden");

        if (!cnxcc_terminate_all("$var(customer)")) {
                xlog("Error terminating customer's calls");
        }

        exit;
}

...

4.5.  cnxcc_terminate_all()

   Terminates all calls of the specified customer/profile

   Return code:
     * 1 - successful
     * -1 - failed, error logged

   Example 1.7. cnxcc_set_max_time()
...
$var(customer)  = "john-doe-123-basic";

if (!cnxcc_terminate_all("$var(customer)")) {
        xlog("Error terminating customer's calls");
}
...

5. Exported RPC Commands

   5.1. cnxcc.active_clients
   5.2. cnxcc.check_client
   5.3. cnxcc.kill_call

5.1. cnxcc.active_clients

   Retrieves all calls grouped by their identifiers.

   Parameters: none

   Example:
            kamcmd cnxcc.active_clients

5.2. cnxcc.check_client

   Retrives all calls from a particular identifier.

   Parameters: client/customer identifier

   Example:
            kamcmd cnxcc.check_client john-doe-123-premium

5.3. cnxcc.kill_call

   Kills an active call using its call ID.

   Parameters: Call-ID

   Example:
            kamcmd cnxcc.kill_call qumojlaahitafih@carlosrdcnx-laptop.site

6. Events

   When a call is forced to end an event route is automatically invoked.
   This route is suited with a fake OPTIONS message containing the call
   ID, ftag and ttag of the original call so it can be located somehow in
   the accounting database.

   Example:
...
event_route[cnxcc:call-shutdown]
{
        xlog("L_INFO", "[$ci]: call killed");

        # perform some kind of notification, database update, email sending, etc
.
}
...

7. Web Interface

   The module contains a web management interface completely optional.
   With it, you can review your calls in real time and hang them up if
   necessary.

   Link: https://github.com/caruizdiaz/cnxcc-web

8. Sample

   Example 1.8. kamailio-cnxcc.cfg
...
route[CNXCC]
{
        $var(client)              = "test-client-0-123-01";
        $var(credit)              = "50";
        $var(cost_per_sec)        = "0.5";
        $var(i_pulse)             = "30";
        $var(f_pulse)             = "6";

        if (!cnxcc_set_max_credit("$var(client)",
                          "$var(credit)",
                          "$var(cost_per_sec)",
                          "$var(i_pulse)",
                          "$var(f_pulse)")) {
                 xlog("Error setting up credit control");
        }
}

event_route[cnxcc:call-shutdown]
{
        xlog("L_INFO", "[$ci]: call killed");


}
...
