The two exchanges, operating from Shivaji Nagar and Trombay, would allegedly use SIM boxes to route international calls locally, and, for a commission, charge those making such calls at local rates. The fraud is known internationally as the ‘SIM box fraud’. Another officer said that the fraud works by bypassing the network used normally for international calls. “As per law, these calls have to pay tariff as per international calls. The SIM box fraud masks international calls as local calls.

Source: Indian Express August 04, 2017 21:50 UTC