EW Voice Firewall: Protect Calls and Unlock New Revenue

How Voice Fraud Drives Revenue Loss and Increases Risk

As regulation of A2P SMS tightens and enforcement against gray routes increases, OTP traffic is rapidly shifting to voice channels like flash calls and pass calls. While this reduces costs for service providers, it leads to declining SMS termination revenue for operators and increases the use of authorization bypass scenarios.

At the same time, voice remains the primary channel for spam and fraud, including caller ID spoofing, robocalling, social engineering, and wangiri attacks. Operators must balance subscriber protection with restoring control over monetization.

Who Benefits
from EW Voice Firewall

Telecom Operators

SMS Aggregators

Win back OTP revenue. EW Voice Firewall blocks flash calls and pass calls, pushing services back to SMS, the higher-margin channel for operators.

Protect subscribers from fraud and unwanted calls. The system detects suspicious voice fraud scenarios and helps minimize reputational risk.

Offer the solution under your own brand. Use a proven white-label product to prevent SMS monetization bypass through voice channels.

Rely on expert support end to end. Eastwind manages the full lifecycle, from traffic evaluation and deployment strategy to rule configuration, analytics, and reporting.

A2P Traffic Monetization

Bring OTP traffic back to the higher-value SMS channel by blocking flash calls and pass calls. Boost A2P authentication revenue and prevent commercial agreement bypass.

Subscriber Protection from Voice Fraud

Stop robocalls, wangiri attacks, and voice-based social engineering in real time, reducing financial losses for subscribers and reputational risks for operators.

Control and Monetization of Outbound Calling

Monetize voice campaigns transparently by redirecting bulk promotional calls from gray routes into official channels through the operator’s or partner’s call center.

[ 01 ]

Flexible Call Handling

More than just blocking: the system can mask caller ID, forward calls to voicemail, or intercept them with automated responses. This reduces false positives and minimizes negative subscriber impact.

[ 02 ]

Seamless Operator Network Integration

Deployed directly in the operator network, the solution controls every call in real time, allowing, blocking, rerouting, or modifying sessions based on smart filtering rules.

[ 03 ]

Data-Driven Detection of Flash Calls and Pass Calls

Built on real traffic data, the system identifies fraud patterns and automatically applies policies to handle suspicious activity.

[ 04 ]

Advanced Reporting and KPI Control

Comprehensive analytics on fraudulent call volumes, including destinations and networks, time trends, the share of processed and blocked calls, and the effectiveness of applied rules.

FAQ

How does EW Voice Firewall detect flash and pass calls?

The system analyzes call parameters and traffic behavior patterns, including caller number uniqueness, high-risk destinations, and recurring calling scenarios. Using statistical models and predefined rules, it can either block the call or apply softer actions such as number masking or call redirection.

How long does integration take?

1 to 3 months is the typical deployment timeline, depending on network architecture, integration points, and call handling scenarios.

What are the system requirements for EW Voice Firewall?

EW Voice Firewall is fully virtualized and works with VMware, Hyper-V, KVM, and OpenStack. It runs on Red Hat Enterprise Linux or Oracle Linux and uses ClickHouse and PostgreSQL for data processing.

Is it necessary to hire additional staff for OTP traffic management?

No. With managed services, Eastwind handles everything from traffic analysis to rule setup. Operators get measurable results and ongoing reporting with no need to expand their teams.

What are the advantages of managed services?

With managed services, a dedicated Customer Success Manager takes full ownership of traffic monitoring, rule configuration, and reporting. Operators and aggregators can free up resources and avoid the overhead of analyzing traffic and constantly updating rules internally.