Test Call Generation (TCG) in Fraud Management: A Detailed Overview

In the telecommunications sector, Test Call Generation (TCG) is a proactive mechanism for detecting, preventing, and managing fraud. With telecom operators facing various types of fraud—ranging from SIM box fraud to CLI fraud—TCG provides a way to regularly monitor and assess the network’s integrity through automated, controlled test calls or messages.

This blog post will explore the role of TCG in fraud management, its functionality, and why it’s indispensable for telecom operators.

TCG is a method used by telecom operators to generate and route test calls across their networks. These test calls simulate regular user activities, such as making phone calls or sending messages, to monitor performance, identify vulnerabilities, detect anomalies, and ensure that their systems are functioning as intended within the network. Unlike actual user calls, these calls are programmed to follow specific patterns and scenarios, allowing operators to assess multiple aspects of the network.

TCG is particularly useful in detecting Subscription Fraud, Wangiri Fraud, IRSF (International Revenue Share Fraud), and other types of telecom fraud.

This testing technology is widely employed to:

• Detect fraud and bypass activities such as SIM box fraud.
• Evaluate quality of service (QoS) for voice, SMS, and data.
• Ensure regulatory compliance for interconnect billing and other legal frameworks.

Telecom fraud is a multi-billion-dollar problem impacting operators worldwide. Fraudsters continuously evolve their tactics, making it essential for operators to stay ahead. Here’s why TCG is a vital component of fraud management:

• SIM Box Fraud: Fraudsters set up multiple SIM cards in a “SIM box” to terminate international calls as local ones, avoiding higher termination fees. TCG detects irregular call patterns that can indicate SIM box activity.
  CLI Manipulation: Fraudsters may manipulate the Caller Line Identification (CLI) to conceal the origin of the call, often leading to fraud. TCG can detect such cases by tracing back the origin of test calls and comparing it with the CLI data.
• Subscription Fraud: Fraudsters obtain services using fake or stolen identities. TCG can help identify unusual usage patterns associated with these accounts.
• Premium Rate Service (PRS) Fraud: Fraudsters may initiate premium-rate calls from within a network to generate revenue illegally. By generating test calls to premium-rate numbers, TCG can spot these fraud attempts.
• PBX Hacking: Fraudsters hack into PBX systems to make unauthorized calls. TCG can simulate PBX call patterns to detect vulnerabilities.

TCG is particularly effective in detecting the following types of telecom fraud:

• SIM Box Fraud: Fraudsters set up multiple SIM cards in a “SIM box” to terminate international calls as local ones, avoiding higher termination fees. TCG detects irregular call patterns that can indicate SIM box activity.
  CLI Manipulation: Fraudsters may manipulate the Caller Line Identification (CLI) to conceal the origin of the call, often leading to fraud. TCG can detect such cases by tracing back the origin of test calls and comparing it with the CLI data.
• Subscription Fraud: Fraudsters obtain services using fake or stolen identities. TCG can help identify unusual usage patterns associated with these accounts.
• Premium Rate Service (PRS) Fraud: Fraudsters may initiate premium-rate calls from within a network to generate revenue illegally. By generating test calls to premium-rate numbers, TCG can spot these fraud attempts.
• PBX Hacking: Fraudsters hack into PBX systems to make unauthorized calls. TCG can simulate PBX call patterns to detect vulnerabilities.

TCG involves the creation of simulated calls that mimic real-world call scenarios. These test calls are then monitored to assess the network’s response and identify any irregularities. Here’s a step-by-step breakdown of the TCG process:

1. Test Script Creation:TCG platforms allow users to create a variety of test call scripts based on known fraud patterns, defining the parameters for the test calls, such as call duration, destination, time intervals, and type (voice, SMS, or data).
   • Simulating international calls to high-risk destinations.
   • Testing premium rate numbers.
   • Generating calls during off-peak hours to detect unusual activity.
2. Test Call Generation: Once the script is created, the TCG system automatically initiates test calls or SMS messages according to the predefined rules. These test calls are routed through the network just like regular calls and distributed across various network points and, possibly, different countries, depending on the scenario.
3. Data Collection: As the calls are made, the TCG system records data such as call quality (e.g., jitter, packet loss), call success rate, and latency. For fraud detection, the system looks for anomalies, such as unusual routing patterns or discrepancies in the expected call termination points.
4. Analysis and Reporting: After collecting the data, the TCG platform analyzes the results and provides detailed reports. Key metrics such as call duration, routing paths, and billing records are analyzed for discrepancies. If irregularities or potential fraud instances are detected, the system can raise alerts for further investigation.
5. Identify Anomalies: Any deviations from expected behavior are flagged as potential fraud indicators. For example, if a test call is routed through an unauthorized gateway or billed incorrectly, it could indicate a vulnerability.
6. Automated Response: In more advanced implementations, the TCG system may be integrated with fraud management platforms that automatically trigger preventive actions, such as blocking suspected fraudsters, rerouting traffic, updating fraud rules, or enhancing security measures to prevent revenue loss.

• Proactive Fraud Detection: With regular and controlled test calls, operators can detect fraudulent activity in real time, preventing large-scale revenue losses.
• Cost Efficiency: TCG reduces the cost associated with manual fraud detection, making it a highly cost-effective solution for monitoring large telecom networks.
• Enhanced QoS Monitoring: In addition to fraud management, TCG allows operators to continuously assess the quality of service (QoS) across different locations and service types, ensuring an optimal user experience.
• Compliance Assurance: By using TCG, operators can ensure they are complying with international telecom regulations and agreements, minimizing the risk of fines or penalties.
• Customization and Scalability: TCG solutions can be customized to meet the specific needs of the operator, whether the focus is on a particular type of fraud or on overall network performance. TCG can be scaled up or down accordingly.

While TCG is a powerful tool, it does have limitations:

• False Positives: TCG can sometimes generate false positives, requiring manual intervention to validate results.
• Complex Setup: Setting up a comprehensive TCG system can be technically complex and requires thorough knowledge of the network and fraud patterns.

To maximize the effectiveness of TCG in fraud management, telecom operators should follow these best practices:

• Regular Testing: Conduct TCG on a regular basis to stay ahead of evolving fraud tactics.
• Diverse Test Scenarios: Use a wide range of test scenarios to cover all potential fraud vectors.
• Real-Time Monitoring: Implement real-time monitoring tools to detect and respond to anomalies immediately.
• Collaborate with Partners: Work with other operators and fraud prevention organizations to share insights and best practices.
• Leverage Advanced Analytics: Use machine learning and AI-driven analytics to enhance the accuracy and efficiency of TCG.

Test Call Generation (TCG) is a powerful tool in the arsenal of telecom operators for combating fraud. By simulating call scenarios and monitoring network behavior, TCG enables operators to detect and prevent fraudulent activities before they cause significant damage. As fraudsters continue to innovate, the importance of TCG in fraud management will only grow.

For telecom operators, investing in robust TCG systems and practices is not just a defensive measure—it’s a strategic imperative to reduce revenue loss, maintain customer trust, and enhance the overall integrity of their networks.

If you’re a telecom operator looking to enhance your fraud management capabilities, consider integrating TCG into your strategy. Stay vigilant, stay secure, and keep your network fraud-free!