A system for controlling traffic between a Home Public Mobile Network (HPMN) and a Visiting Public Mobile Network (VPMN) of a roaming mobile station is provided. The system includes a TR probe for detecting a traffic redirection (TR) attempt for the roaming mobile station, by observing exchange of at least one registration message between the VPMN and the HPMN. The system further includes an anti-TR unit for thwarting the TR attempt by sending one or more registration response messages in response to the at least one registration message received from a switch.