Voice Firewall

Cellusys Call Control is a solution that provides a single point in the network to detect and prevent voice fraud such as IRSF, wangiri, and SIM boxes, and provide centralised call visibility for business intelligence based on realtime control of call setup and management.  

  • Centralised voice fraud control
  • Realtime detection and prevention
  • Visibility for business intelligence
  • Reduced operational complexity 
  • Simple integration

Impact of call fraud

Subscriber privacy is violated and sensitive info exposed. Subscribers lose trust and move to alternate channels. The network assumes the costs of fraudulent charges which cannot be billed. Arbitrage and shortstopping abuse wholesale agreements causing huge losses to the targeted network, and loss of billable roaming revenue increases costs while depleting revenues. Call fraud is more than an nuisance to subscribers, and has real financial impacts for mobile network operators.



IRSF International Revenue Share Fraud is the most commonly reported voice fraud, costing over 5 billion annually. IRSF inflates traffic to high cost international destinations by tricking subscribers to call these destinations by using techniques such as wangiri, PBX Hacking, or stolen devices. The calls may be short stopped, benefiting both the perpetrating network and the shortstopping network.


SIM box is a type of call fraud used to route calls between networks without paying agreed interconnect fees. SIM boxes can be physical devices with multiple SIM cards used to terminate calls on the victim network, or can be an application that uses subscribers’ phones and service to terminate calls and SMS on the victim network. This re-routing of traffic costs MNOs 6.8 billion per year. The call recipient receives the call from a local number, and the operator is defrauded of the value of the interconnect rate that has been bypassed.


Spoofing occurs when the interconnect service provider changes the calling line identity (CLI) of a call to a local number, resulting in no interconnect revenue to the receiving operator.


Applying pattern analysis and recognition to the processing of the signalling related to call setup and management, as well as roaming status checks, these various call fraud methods can be categorised for further action.


Wangiri is commonly referred to as “missed call” or “one ring” fraud. Wangiri costs operators around 1.3 billion annually and is frequently used as a means of generating traffic for IRSF fraud. The perpetrator calls the victim but ends the call before the call is answered. This incites the victim to redial the missed number, at a high cost to the subscriber. The perpetrating network benefits from the minutes generated and either the subscriber or the home network is responsible for the cost.

Flash Calls

Flash Calls are an alternative to SMS as a method of 2 factor authentication (2FA). A call is placed from a particular number range, and the application immediately recognises some digits of this phone number as the authentication code. The call is not answered and therefore generates no revenue for the receiving network. This depletes valuable A2P SMS revenue, and the cost to operators can not yet be estimated. 

FMS Integration

CCC provides APIs to allow immediate action to be taken with integrated fraud management systems, provided by Cellusys or by the operator. 


Incoming fraudulent calls can be blocked and outgoing calls to fraudulent destinations can be prevented, saving subscribers from fraudulent charges and protecting valuable revenue streams to the operator.

Accessible Reporting

Equipped with powerful (yet agile) reporting and alerting features, not only will your network be secure, you can be sure to have the most accurate information about your network traffic and security at your fingertips.

Customise real-time alerts to be notified the moment a threat occurs.

Everyone on your team can be provided proper access levels and customise reports to suit their individual needs (no matter their level of technical expertise) thanks to the intuitive GUI.

Easily set alerts or publish reports as broad as traffic overview or drill down to monitor a suspicious caller ID. Troubleshoot VIP complaints and monitor message volumes with the touch of a button.


From the first day of deployment, pre-defined rules ensure all known threats are blocked. From here, the rules engine, using advanced matching algorithms, not only detects the threats but also provides valuable intelligence in real time, assisting security teams to actively stop any new undefined threats and identify the source.

New policies can be created and implemented immediately without relying on third parties or software updates. Users have full access to the protocol, and can easily customise the flexible rules engine via the user-friendly web interface to implement broad policies as well as attain fine-grained control.

Signalling Providers and Signalling Hubs

Signalling is your business — at least make it secure.

We have provided many Tier1 signalling hubs with the capability to control and secure their signalling.

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SS7 Firewall

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Managed Service for Security


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