Interconnect Bypass
What is it?
A carrier-specific attack
Interconnect Bypass (aka toll bypass fraud, interconnect fraud, GSM Gateway fraud, or SIM Boxing) is the unauthorized insertion of traffic onto another carrier’s network. In this scenario, fraudsters make international calls appear to be cheaper than domestic calls, effectively bypassing the normal payment system for international calling. In Interconnect Bypass, the fraudsters will typically sell long-distance calling cards overseas. When customers call the number on the cards, operators can switch the call to make it seem like a domestic call. While this type of telecom fraud doesn’t directly impact the customer, it certainly drains carriers’ budgets.
How?
A customer makes a call to an international phone card
The call is connected and an operator routes it to a different carrier network
Impact:
This does not directly impact the customer
Carrier minutes are used for fraud, not the customer's
How to Prevent?
This is a type of fraud that does not impact the customer. It has carrier implications that may be passed to the customer.
Prevention starts with good PBX security hygiene (passwords, CDR reviews, periodic checkups on activity on the account).