The global mobile communications market continues to grow—and with it, the number of SMS fraud threats is also on the rise. For instance, telecom operators lose billions in revenue every year because 35% of all commercial A2P text messages are sent via “grey” routes. In 2023 alone, SMS fraud led to global financial losses of $5.8 billion. Discover the key capabilities an anti-spam system for telecom have to help mobile providers prevent losses and boost profits through effective SMS traffic monetization.
 

Blocking Spam in Telecom Networks: Key Criteria for an Effective System

Anti-spam systems protect telecom networks from spam messages which harm operators in two key ways:

• lead to potential revenue loss when unscrupulous aggregators or content providers disguise international A2P text messages as local ones by using SIM boxes or spoofing sender numbers
• undermine mobile users' loyalty, as those targeted by spam attacks may share personal or financial information with fraudsters and suffer direct monetary losses

How the EW SMS Firewall Helps Monetize A2P Traffic at Zain Kuwait

A modern SMS firewall designed to combat spam texts must be capable of filtering all types of traffic, offer ease of use, be flexible and scalable, and integrate seamlessly with the operator’s existing network infrastructure. Let’s look at the key criteria for selecting the optimal SMS fraud prevention solutions.


By 2027, telecom operators' financial losses from “grey”-route SMS traffic are projected to decrease by 66% thanks to the adoption of SMS Firewall
Source: SMS Firewalls: Future Outlook, Regional Analysis & Market Forecasts 2023–2027 (Juniper)
 

Sign 1: Comprehensive SMS Filtering for Telecom Providers to Detect Spam and Fraud

SMS spam filters help operators in detecting and blocking SMS fraud, protecting subscribers from fraudulent attacks and shielding themselves from direct monetary losses. To achieve this, modern SMS Firewalls analyze both the sources of traffic and the content carried in the text messages.

AI-Based Filtering for Efficient Fraud Detection

Fraud schemes are constantly evolving, making them increasingly difficult to combat using traditional methods. An AI module enhances automated SMS scam detection accuracy and speeds up the process through intelligent text message analysis.

In real time, the AI module identifies spam text messages using natural language processing (NLP) models. As it analyzes SMS traffic, the system learns automatically and begins predicting potential fraud patterns. This enables the firewall to block “grey” text messages without relying solely on static rules.

“Using AI in the fight against fraud significantly improves the detection of unwanted messages, helping operators and aggregators reduce financial losses more effectively.
The Eastwind AI module is part of the EW SMS Firewall solution and can be deployed on demand to provide real-time fraud protection. The language models it’s built on can be trained to adapt to local specifics during operation.”

• Sender identifiers for P2P messages—IMSI and MSISDN
• Sender identifiers for A2P messages—Alphanumeric Sender ID and short codes.

Case Study. Eastwind Implements URL Phishing Protection for Zain Kuwait in 2024

Before full deployment in SMS infrastructure, we conducted a pilot launch and detected 1,000 SMS messages containing malicious links within just one month. Now, this type of traffic is automatically blocked, and the operator receives detailed reports. The network of Zain Kuwait is under defense.

Learn more about EW SMS Firewall at Zain Kuwait

For an anti-fraud system to fully meet business needs and to provide customer protection, it must filter all traffic. To achieve this, the system must be highly flexible in terms of network infrastructure integration capabilities.
 

Sign 2: Support for Multiple SMS Transmission Protocols among Mobile Operators

To provide comprehensive traffic protection across all network layers, an SMS Firewall must support a variety of message transmission protocols and integrate seamlessly with the operator’s existing systems.

Compatibility with SMPP, MAP, and Diameter Protocols

Support for key telecom protocols allows the SMS Firewall to connect to the operator’s network without requiring infrastructure changes. The main supported protocols include:

• SMPP (Short Message Peer-to-Peer Protocol): Used to analyze commercial text messages sent by the operator’s SMS services (bulk, VAS) as well as those from partners such as SMS providers and aggregators.
• MAP over SS7 (Signaling System No. 7): Enables analysis of both commercial A2P messages and peer-to-peer (P2P) mobile users traffic.
• Diameter: Facilitates SMS exchange over 4G/LTE networks.

Adaptability of Security Solutions to Operator’s Architecture

Messaging systems are typically built on the SS7 protocol—but not always. Some mobile providers use message brokers like Apache Kafka. To integrate with such setups, the standard architecture of the SMS Firewall must be flexible enough to accommodate these variations.

Case Study. Integrating the EW SMS Firewall with Apache Kafka for an African Operator

One of Eastwind’s clients in Africa built their messaging system on Apache Kafka. To integrate it with the EW SMS Firewall, we made targeted architectural adjustments. For instance, we moved parts of the message validation process from external systems into the core firewall engine, introduced an Apache Kafka queueing service, and designed and implemented a custom proxy node.

As a result, the system now processes SMS messages in under one second. These enhancements enabled us to successfully adapt the security solution to the operator’s specific infrastructure needs.

How We Integrated the EW SMS Firewall with Apache Kafka
 

Sign 3: SMS Firewall Implementation Analytics and Monitoring for Telecom Operators

Uninterrupted operation is critical for SMS Firewall implementation for telecom operators. Even a one-hour outage can allow a scam text messages attack or large volumes of “grey” traffic to slip through. Built-in monitoring tools help prevent such scenarios by ensuring that the system remains stable and fully operational.

Real-Time Analytics

Modern anti-fraud systems come equipped with:

• Dashboards for visualizing data
• Customizable reports based on specific criteria, allowing business to quickly access the most relevant metrics. For example, reports can reveal warning signs: whether any new A2P message senders are attempting to bypass the system by spoofing sender IDs.

The EW SMS Firewall dashboard provides statistics on the volume of both international and local A2P messages sent through mobile network
 

Real-time analytics is especially crucial for business during spam campaigns, when fraudsters launch large-scale distributions of malicious messages. Early detection is key to stopping an attack quickly. The EW SMS Firewall includes automated tools designed for this purpose—they can detect mass messaging activity in real time, without relying on pre-set rules or blacklists.

Integration with External Monitoring Systems

Integrating with solutions like Prometheus, Zabbix, and similar platforms enables centralized oversight of both the anti-fraud system and the operator’s network. It's especially useful when system performance data is visualized through intuitive dashboards, making monitoring more efficient and accessible.


Thanks to integration with the Prometheus monitoring system and the Grafana visualization platform, our clients can monitor both hardware performance and system operations directly within the EW SMS Firewall interface


Integration of the EW SMS Firewall with Zabbix enables system performance monitoring, trigger configuration, and alert management. The example shown features a dashboard displaying real-time trends in incoming and outgoing traffic

Data Logging

SMS Firewalls are regularly updated by specialists who adjust filtering rules and manage blacklists and whitelists for protecting networks and subscribers from SMS spam. Event logging allows for full traceability of these changes by recording who made the update, when it was made, and why. In the EW SMS Firewall, specialists can also add comments to any actions involving lists or rules—providing clear context for each change and making it easy to understand the rationale behind every adjustment.
 

Sign 4: Scalability and Performance of the Security Solution

An anti-spam system must be prepared to handle increasing traffic loads and evolving functionality—all while maintaining high availability and fault tolerance.

High Traffic Handling

The performance of an anti-spam system for telecom operators is typically measured in TPS—Transactions Per Second. The solution must reliably handle the expected load and remain stable even at peak volumes. When selecting a security solution for business, it's essential to compare your network’s TPS with the system’s capacity. If the platform’s TPS falls short, it may let spam text messages slip through during traffic surges. For example, the EW SMS Firewall can process up to 15,000 SMS messages per second.

Reliability

To effectively block spam messages in telecom networks, an SMS Firewall must operate continuously with no downtime. A 99.999% system availability rate ensures uninterrupted traffic analysis, spam filtering, and A2P fraud prevention.

Scalability

To make the investment in an SMS firewall worthwhile, the security solution must scale easily. For instance: A growing subscriber base may require managing larger blacklists and whitelists. New fraud tactics may demand rapid implementation of updated filtering rules. Infrastructure must scale without downtime during updates and enhancements. These capabilities should be built into the anti-fraud system to ensure that performance remains unaffected during scaling.
 

“Whitelists are essential to prevent SMS Firewalls from blocking messages from legitimate high-LTV senders—even if their messages appear suspicious. It’s a way to protect operator revenue, provide good customer experience and maintain customer loyalty.
The EW SMS Firewall supports whitelists with 1.5 million numbers or more. We scaled this feature when one of our clients required it.”

— Andrey Alematsev,
Product Manager, the EW SMS Firewall

Sign 5: Managed Services Support

Fraudsters are constantly inventing new ways to bypass legitimate message delivery channels. To detect and stop these evolving threats in time, telecom operators must monitor traffic daily and continuously update filtering rules—tasks that go far beyond the scope of standard technical support, which typically covers only system updates and maintenance. This is where Managed Services come in.

With the Managed Services model, businesses don’t need to expand their in-house teams, hire, or train specialists to manage the SMS Firewall. Instead, the vendor takes full responsibility for daily operations—bringing deep product expertise, which reduces the risk of misconfiguration or oversight. This approach enables faster system deployment, more effective prevention of financial losses due to SMS fraud and higher operational efficiency. 
 

“For fraud detection and blocking we use both preventive and reactive strategies. For example, AI and machine learning algorithms help us identify SIM boxes and predict new fraud schemes, enabling us to block them even faster. In addition, we monitor clients’ international traffic daily, analyze CDRs, update and test filtering rules and blacklists—all to block “grey”-route A2P SMS and maximize client revenue.”

— Irina Timofeeva,

Eastwind Customer Success Manager

 

How to Choose an SMS Firewall for Comprehensive SMS Traffic Security for Operators

An SMS Firewall helps businesses boost revenue by monetizing A2P traffic and strengthening mobile users loyalty through effective spam protection. However, not all security solutions perform equally well. The table below outlines the minimum set of criteria a system must meet to successfully monetize SMS traffic and protect subscribers. Use it to assess your current SMS Firewall or evaluate a potential solution before deployment.

Evaluation Criteria for an SMS Firewall

 

Basic Functions

1. Comprehensive Traffic Filtering

2. Support for Multiple SMS Transmission Protocols

3. Centralized Monitoring and Real-Time Analytics

4. Scalability and Fault Tolerance (99.9% System Availability)

5. Managed Services Support

Additional Features of an SMS Firewall

6. AI-Powered Real-Time Traffic Processing and Fraud Blocking

7. Flexible Traffic Filtering Rules

8. URL Scanner

9. Granular Control Over Message Handling

10. Custom Integration Capabilities