A call center is a centralized department that handles inbound and outbound communications—primarily phone calls—from customers or clients. These centers may be housed within an organization or outsourced to a third-party vendor specializing in customer service and telecommunication solutions.

A call center is a centralized department that handles inbound and outbound communications—primarily phone calls—from customers or clients. These centers may be housed within an organization or outsourced to a third-party vendor specializing in customer service and telecommunication solutions.

Types of Call Centers

There are three common types of call centers:

1. Inbound Call Centers

These centers handle a high volume of incoming calls. An Interactive Voice Response (IVR) system may answer the call initially and use Automatic Speech Recognition (ASR) technology to understand and respond to customer inquiries. If necessary, the system routes the caller to a live agent for further assistance.

2. Outbound Call Centers

In outbound centers, agents initiate calls to customers or leads. These calls may serve purposes such as lead generation, telemarketing, conducting surveys, customer satisfaction follow-ups, or appointment scheduling.

3. Blended Call Centers

Blended call centers manage both inbound and outbound calls. This setup allows for efficient use of agent time and resources, especially in environments where call volumes fluctuate.

1. What is Open Source Software?

Open source software (OSS) is software with publicly available source code. Anyone can view, modify, and distribute it. These solutions are often developed collaboratively and maintained by community contributions, which makes them highly adaptable and cost-effective.

Examples of Popular Open Source Software:

• Linux (Operating System)

• SugarCRM (Customer Relationship Management)

• ICTFax (fax server software)

• ICTCore (open source unified communications framework)

• ICTCrm (CRM Software integrated with CTI)

• LibreOffice (Office Suite)

• Mozilla Firefox (Web Browser)

• Apache (Web Server)

2. Benefits of Open Source Software

Transparency

You can track changes in the code and understand how your data is processed—no hidden backdoors or proprietary restrictions.

Reliability

Unlike proprietary software, which may depend on a single company for updates, open source projects are community-driven, increasing their longevity and reliability.

Flexibility

Open source software is highly customizable. Organizations can tailor features to suit specific business needs.

Lower Cost

The software itself is free. Costs are usually associated with implementation, support, and maintenance, not licensing.

Collaboration

Open source fosters a strong community that contributes enhancements, fixes, and documentation, offering valuable support and innovation.

Scalability

OSS solutions can scale up or down depending on the call volume, making them suitable for businesses of all sizes.

Support

Most open source projects have extensive documentation, active forums, and commercial support options.

3. Popular Open Source Software Solutions for Call Centers

When it comes to building a robust and cost-effective call center solution, open-source platforms offer flexibility, scalability, and community support. Below are some of the most widely adopted open-source software platforms that serve as the backbone of modern call centers. These solutions range from telephony engines to complete contact center suites, each tailored to specific needs and deployment scales.

1. Asterisk – The Open Source Telephony Engine

Developed by Digium, Asterisk is one of the most well-known and widely used open-source PBX (Private Branch Exchange) systems. It transforms a standard computer into a powerful communications server, allowing businesses to create their own customized telephony solutions. Asterisk acts as the foundational engine for many other applications in the telecom world.

• Key Features: Interactive Voice Response (IVR), call routing, voicemail, conference calling, and support for various codecs and protocols (SIP, IAX, etc.).

• Ideal Use Case: Perfect for businesses or developers looking to build a tailored call center or IP PBX solution from scratch using modular components.

• More Info: What is Asterisk

2. FreeSWITCH – Scalable Real-Time Communication Platform

FreeSWITCH is a versatile open-source telephony platform designed for large-scale deployments. It supports voice, video, text messaging, and WebRTC, making it suitable for building complex communication applications. FreeSWITCH is often seen as a modern alternative to Asterisk for projects requiring high scalability and media versatility.

• Key Features: Native support for WebRTC, Session Initiation Protocol (SIP), conferencing, speech recognition, and extensive codec compatibility.

• Ideal Use Case: Ideal for businesses and developers who need to implement real-time voice/video solutions or high-performance telecom infrastructure.

• More Info: All About FreeSWITCH

3. ICTCore – Unified Communications Framework for Developers

ICTCore is a unified communications framework built on top of FreeSWITCH, designed to simplify the development of telephony applications. It provides a programmable communication engine with RESTful APIs, allowing integration of voice, SMS, fax, and email features into business applications with ease.

• Key Features: Developer-friendly APIs, modular design, inbound and outbound call processing, and support for multi-channel communication.

• Ideal Use Case: A great choice for software developers and businesses looking to embed communication capabilities within their own systems or applications.

• More Info: ICTCore

4. ICTBroadcast – Unified Auto Dialer and Call Center Suite

ICTBroadcast is a comprehensive and multi-tenant unified communications and AI powered autodialer software solution. Based on Asterisk, it supports various campaign types, including voice, SMS, email, and fax, along with predictive and power dialing capabilities. ICTBroadcast offers a web-based GUI, making it user-friendly and ideal for non-technical users.

• Key Features: WebRTC integration, automated call distribution, multi-channel campaigns (voice, fax, SMS, email), agent support, and REST API integration.

• Ideal Use Case: Best suited for telemarketing firms, customer service departments, and organizations that need to run notification or survey campaigns.

• More Info: ICTBroadcast

5. VICIdial – Complete Call Center Suite

VICIdial is a full-featured, web-based contact center suite built on top of Asterisk. It supports both inbound and outbound calling and includes a range of features required for professional call centers. With a large global user base, VICIdial is known for its community support and wide range of telephony features.

• Key Features: Automatic Call Distribution (ACD), real-time agent monitoring, call recording, campaign management, and support for multiple languages.

• Ideal Use Case: Suitable for small to medium-sized businesses seeking a reliable and CRM-integrated call center solution without heavy licensing fees.

• More Info: VICIdial

These open-source solutions empower businesses of all sizes to build efficient and scalable call centers without the cost of proprietary software. Whether you're a developer looking for integration flexibility or an enterprise seeking a ready-to-deploy solution, these platforms offer a solid foundation for all your communication needs.

4. Call Center Infrastructure

The infrastructure of a call center is just as crucial as the software. It includes three core components:

1. Telecommunication Network

• Public Switched Telephone Network (PSTN)

• Routers, Ethernet Switches, and Internet Access

• VoIP integration via SIP trunks or PBX systems

2. Hardware

• Desktop computers or thin clients for agents

• VoIP phones or headsets

• PBX system or gateways

• Servers for hosting software

• Interactive Voice Response (IVR) systems

• Call recording equipment

3. Software

• Operating System (Linux/Windows)

• CRM Software (SugarCRM, SuiteCRM)

• Call Center Software (Asterisk, ICTBroadcast, etc.)

• Database and reporting tools

5. Setting Up and Configuring the Software

Here’s a general step-by-step guide for setting up your call center with OSS:

Step 1: Choose and Install Software

Select suitable call center software (e.g., Asterisk, FreeSWITCH, VICIdial). Install it on a Linux-based server.

Step 2: Configure Telephony Hardware

Connect VoIP hardware, SIP trunks, or telephony cards for making and receiving calls.

Step 3: Create Extensions

Set up SIP or softphone extensions for each agent in your system.

Step 4: Set Up Call Routing

Define call flow using IVR menus or ring groups to guide callers to appropriate agents.

Step 5: Configure Call Queues

Manage incoming call flow during busy times with call queues to improve customer wait time experience.

Step 6: Enable Call Recording

Enable call logging and recording for training, analysis, or legal compliance.

Step 7: Integrate CRM

Link your call center software with CRM systems to access customer data and call logs.

Step 8: Test the Setup

Perform test calls to ensure routing, IVR, agent connections, and other features are working as expected.

Step 9: Train Agents

Provide hands-on training for agents on how to use the phone system, CRM, and call handling procedures.

Step 10: Monitor and Maintain

Regularly update software, check system logs, monitor performance, and implement security best practices.

6. Conclusion

Building a call center using free and open source software like Asterisk, FreeSWITCH, ICTCore, or VICIdial offers an affordable and scalable solution for small to medium businesses. Although setting up such a system requires technical knowledge and careful planning, the long-term benefits—customization, cost savings, and flexibility—are well worth it.

However, remember that open-source solutions may not offer the same level of out-of-the-box support as commercial platforms. Carefully evaluate your organization’s needs and be prepared to invest time in setup, training, and ongoing maintenance.