The extent of revenue loss to interconnect bypass or simbox activity is still largely unknown to many Operators and MVNOs. Not only does it have a direct impact on the Operators’ or MVNOs’ bottom line, but is also responsible for traffic disruption on networks, causing indirect financial damage. SIM boxes do not allow the delivery of the Calling Line Identity (CLI). Therefore, legitimate customers, being called via simboxes, may complain about the unavailability of services they would otherwise expect to be able to use. The quality of service also suffers due to network congestion on the call, the bad quality due to traffic and the excessive number of dropped calls. Finally, inbound roamers may experience problems in receiving calls if simboxes try to bypass calls to routing numbers (MSRN) used to terminate calls to inbound roamers.