Anti Fraud und Security Services: Methods.


Also known as a “ping call” or a “one ring and cut” call – a very short call with no successful connection. The scammer uses either an expensive target or a premium rate number as a phone number and generates revenue from that number when the customer – who received that Wangiri call – calls back. The scammer tries to keep the callback connected for as long as possible to generate the highest revenue.

Bypass Detection

The A1 Wholesale SIM Box Detection Service detects all SIM boxes and bypasses known fraud scenarios on the market.

A-Number Verification

The A1 A-Number Verification Service makes it possible to identify manipulated telephone calls; automated evaluations help to make these fraudulent activities visible. The caller’s real telephone number is replaced with a substitute number so that the international telephone provider that was commissioned to forward the call saves on costs.

Depending on the origin of the telephone call, the called subscriber’s telephone providers charge a different rate to the international telephone provider. To avoid high costs, the call number of the calling subscriber is replaced by one that triggers lower costs.

OTT Detection

The A1 OTT Detection Service makes it possible to simulate the irregular delivery of a telephone call via over the top telephone providers (e.g. via apps on the mobile phone) and thus make the extent of the fraud visible.


This new test method does not require any special test numbers. On the one hand, this makes it harder for the fraudsters to detect the tests, while on the other hand, the test process is easier to implement because there is no need to provide test numbers. H.O.R.S.T. stands for Home Operator Real Subscriber Testing.

SIM BOX Locator

This service extension allows for the fraudsters’ exact location to be pinpointed in real time.


The service extension allows detected SIM boxes to be blocked automatically.

Your advantages

  • Smart and flexible test adaptation making it possible to react quickly to new fraud scenarios
  • Intelligent service extensions allow an even more efficient and faster approach to detecting fraudsters
  • Our free trial allows you to test our services

Our expert know-how also provides support to minimize lost sales due to fraud.

A1 Voice

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