CALL-CENTER module

Admin Guide

Overview

The Call Center module implements an inbound call center system with call flows (for queueing the received calls) and agents (for answering the calls).

The module implements the queueing system, the call distribution to agents, agents managements, CDRs for the calls, statistics on call distribution and agent’s activity - basically everything except the media playback (for the queue). This part must be provided via a third party media server (FreeSwitch, Asterisk or others).

How it works

The main entities in the modules are the flows (queues) and agents.

DB tables

Each entity has a corresponding table in the database, for provisioning purposes - the cc_flows and cc_agents tables, see DB schema. Data is loaded at startup and cached into memory ; runtime reload is possible via the MI commands (see the cc_reload command in cc mi commands).

Additionally there is a table cc_cdrs for writing the CDRs - this operation is done in realtime, after the call in completed, covering all possible cases: call was dropped while in queue, call was rejected by agent, call was accepted by agent, call terminated with error - NOTE that a call may generate more than one CDR (like call rejected by agent A, and redistributed and accepted by agent B).

The cc_calls table is used to store ongoing calls, regardless it’s state (in queue, to the agent, ended). It is populated at runtime by the module and queried at startup. This table should not be manually provisioned.

Call Flows

A flow is defined by a unique alhanumerical ID - the main attribute of a flow is the skill - the skill is a capability required by the flow for an agent to be able to answer the call ; the concept of skills is the link between the flows and the agents - telling what agents are serving what flows - the flows require a skill, while the agents provide a set of skills. Agents matching the required skill of a flow will automatically receive calls from that flow.

Additional, the flow has a priority - as agents may server multiple flows in the same time (based on skills), you can define priorities between the flows - if the flows has a higher priority, its calls will be pushed (in deliver to agents and queing) in front of the calls from flows with a lower priority.

Optionally, the flow may define a prependcid - a prefix to be added to the CLI (Caller ID) when the call is delivered to the agents - as an agent may receive call from multiple flows, it is important for the user to see which was the queue a call was received.

In terms of media announcements, the flow defines the message_welcome (optional, to be played in the call, before doing anything with the call) and message_queue (mandatory, the looping message providing infinite on hold media IMPORTANT - this message must cycle and media server must never hung up on it. Both announcements are provided as SIP URIs (where the call has to be sent in order to get the playback).

Agents

An agent is defined by a unique alhanumerical ID - the main attribute of an agent is its the set of skills and its SIP location. The set of skills will tell what calls to be received (from which flows, based on the skill matching); the location is a SIP URI where to call must be sent in order to be answered by the agent.

Additionally, the agent has a initial logstate - if he is logged in or not (being logged in is a must in order to receive calls). The log state may be changed at runtime via a dedicated MI command cc_agent_login, see cc mi commands.

There is a wrapup_time defined, saying the time interval for an agent before getting a new call from the system (after he finished a call).

Dependencies

OpenSIPS Modules

The following modules must be loaded before this module:

• b2b_logic - B2bUA module
• database - one of the SQL DB modules

External Libraries or Applications

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

• None.

Exported Parameters

db_url (string)

SQL address to the DB server — database specific. This must be the Database holding the provisioning tables (cc_flows, cc_agents and cc_calls tables).

Set db_url parameter

...
modparam("call_center", "db_url",
  "mysql://opensips:opensipsrw@localhost/opensips")
...

acc_db_url (string)

SQL address to the DB server — database specific. This must be the Database where the CDRs table (cc_cdrs) is located.

Set acc_db_url parameter

...
modparam("call_center", "acc_db_url",
  "mysql://opensips:opensipsrw@localhost/opensips_cdrs")
...

b2b_scenario (string)

The name of the B2B scenario that is used by the module for handling the calls in the queue. This is an advanced options and you should not change it unless you really understand what you are doing.

The module provides an B2B scenario file scenario_callcenter.xml located in the module directory. The name of this scenario from this file (which must be loaded via the b2b_logic module) must match the b2b_scenario parameter.

Default value is “call center”.

Set b2b_scenario parameter

...
modparam("b2b_logic", "script_scenario", "/etc/opensips/scenario_callcenter.xml")
modparam("call_center", "b2b_scenario", "call center")
...

wrapup_time (integer)

Time for an agent between finishing a call and receiving the next call from the system. Even if there are queued calls, the module will not deliver call to agent during this wrapup interval.

Default value is “30 seconds”.

Set wrapup_time parameter

...
modparam("call_center", "wrapup_time", 45)
...

Exported Functions

cc_handle_call(flowID)

This must be used only for initial INVITE requests - the function pushs the call to be handled by the call center module (via a certain flow/queue).

This function can be used from REQUEST_ROUTE.

The flowID mandatory parameter is the ID of the flow to handle this call (push the call to that flow). This can be a variable or a static string.

The function returns TRUE back to the script if the call was successfully pushed and handled by the Call Center engine. IMPORTANT: you must not do any signaling on the call (reply, relay) after this point.

In case of error, FALSE is returned to the script with the following return codes:

• -1 - unable to get the flow ID from the parameter;
• -2 - unable to parse the FROM URI;
• -3 - flow with FlowID not found;
• -4 - no agents logged in the flow;
• -5 - internal error;

cc_handle_call usage

...
if (is_method("INVITE") and !has_totag()) {
  if (!cc_handle_call("tech_support")) {
    send_reply("403","Cannot handle call");
    exit;
  }
}
...

Exported Statistics

Global statistics

ccg_incalls

Total number of received calls. (counter type)

ccg_awt

Global avg. waiting time for calls. (realtime type)

ccg_load

Global load (across all flows). (realtime type)

ccg_distributed_incalls

Total number of distributed calls. (counter type)

ccg_answered_incalls

Total number of calls answered by agents. (counter type)

ccg_abandonned_incalls

Total number of calls terminated by caller before being answered by agents. (counter type)

ccg_onhold_calls

Total number of calls in the queues (onhold). (realtime type)

ccg_free_agents

Total number of free agents (across all flows). (realtime type)

Per-flow statistics (one set for each flow)

ccf_incalls_flowID

Number of received calls for the flow. (counter type)

ccf_dist_incalls_flowID

Number of distributed calls in this flow. (counter type)

ccf_answ_incalls_flowID

Nnumber of calls from the flow answered by agents. (counter type)

ccf_aban_incalls_flowID

Number of calls (from the flow) terminated by caller before being answered by agents. (counter type)

ccf_onhold_incalls_flowID

Number of calls (from the flow) which were put onhold. (counter type)

ccf_queued_calls_flowID

Number of calls which are queued for this flow. (realtime type)

ccf_free_agents_flowID

Number of free agents serving this flow. (realtime type)

ccf_etw_flowID

Estimated Time to Wait for this flow. (realtime type)

ccf_awt_flowID

Avg. Wating Time for this flow. (realtime type)

ccg_load_flowID

The load on the flow (number of queued calls versus number of logged agents). (realtime type)

Per-agent statistics (one set for each agent)

cca_dist_incalls_agnetID

Number of distributed calls to this agent. (counter type)

cca_answ_incalls_agentID

Nnumber of calls answered by the agent. (counter type)

cca_aban_incalls_agentID

Number of calls (sent to this agent) terminated by caller before being answered by agents. (counter type)

cca_att_agentID

Avg. Talk Time for this agent (realtime type)

Exported MI Functions

cc_reload

Command to reload flows and agents definition from database.

It takes no parameter.

MI FIFO Command usage:

opensipsctl fifo cc_reload

cc_agent_login

Command to login an agent into the Call Center engine.

It takes two mandatory parameters, the ID of the agent and the new login state (0 - log off, 1 - log in)

MI FIFO Command usage:

opensipsctl fifo cc_agent_login agentX 0

cc_list_queue

Command to list all the calls in queuing - for each call, the following attributes will be printed: the flow of the call, for how long the call is in the queue, the ETW for the call, call priority and the call skill (inherited from the flow).

It takes no parameter.

MI FIFO Command usage:

opensipsctl fifo cc_list_queue

cc_list_flows

Command to list all the flows - for each flow, the following attributes will be printed: the flow ID, the avg. call duration, how many calls were processed, how many agents are logged, and how many onging calls are.

It takes no parameter.

MI FIFO Command usage:

opensipsctl fifo cc_list_flows

cc_list_agents

Command to list all the agents - for each agent, the following attributes will be printed: agent ID, agent login state and agent state (free, wrapup, incall).

It takes no parameter.

MI FIFO Command usage:

opensipsctl fifo cc_list_agents

cc_list_calls

Command to list all the ongoing calls - for each call, the following attributes will be printed: call ID, call state (welcome, queued, toagent, ended), call duration, flow it belongs to, agent serving the call (if any).

It takes no parameter.

MI FIFO Command usage:

opensipsctl fifo cc_list_agents

cc_reset_stats

Command to reset all counter-like statistics.

It takes no parameter.

MI FIFO Command usage:

opensipsctl fifo cc_reset_stats

Exported Pseudo-Variables

NONE

Developer Guide

Available Functions

NONE

Frequently Asked Questions

Q: Where can I find more about OpenSIPS?

Take a look at http://www.opensips.org/.

Q: 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 OpenSIPS release should be sent to users@lists.opensips.org and e-mails regarding development versions should be sent to devel@lists.opensips.org.

If you want to keep the mail private, send it to users@lists.opensips.org.

Q: How can I report a bug?

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

Contributors

By Commit Statistics

Top contributors by DevScore⁽¹⁾, authored commits⁽²⁾ and lines added/removed⁽³⁾

#	Name	DevScore	Commits	Lines++	Lines—
1.	Bogdan-Andrei Iancu (@bogdan-iancu)	46	6	4619	21
2.	Razvan Crainea (@razvancrainea)	13	10	66	100
3.	Stefan Darius (@dariusstefan)	12	4	703	107
4.	Vlad Paiu (@vladpaiu)	3	1	13	4
5.	Liviu Chircu (@liviuchircu)	3	1	5	5
6.	Dusan Klinec (@ph4r05)	3	1	1	1

(1) DevScore = author_commits + author_lines_added / (project_lines_added / project_commits) + author_lines_deleted / (project_lines_deleted / project_commits)

(2) including any documentation-related commits, excluding merge commits

(3) ignoring whitespace edits, renamed files and auto-generated files

By Commit Activity

#	Name	Commit Activity
1.	Stefan Darius (@dariusstefan)	Jun 2026 - Jul 2026
2.	Razvan Crainea (@razvancrainea)	Mar 2014 - Jun 2026
3.	Bogdan-Andrei Iancu (@bogdan-iancu)	Mar 2014 - Feb 2017
4.	Dusan Klinec (@ph4r05)	Dec 2015 - Dec 2015
5.	Liviu Chircu (@liviuchircu)	Jun 2014 - Jun 2014
6.	Vlad Paiu (@vladpaiu)	Mar 2014 - Mar 2014

(1) including any documentation-related commits, excluding merge commits

Documentation

Contributors

Last edited by: Razvan Crainea (@razvancrainea), Bogdan-Andrei Iancu (@bogdan-iancu).

License

All documentation files (i.e. .md extension) are licensed under the Creative Common License 4.0