ITU-T Recommendations

Since the rapid development of the fourth generation (4G) based on the Internet protocol (IP) multimedia subsystem (IMS) network generated the renovation on the network architecture and the service mode, spoofed calls could cause security and financial threats as well as creating new difficulties to terminal users and operators alike. The difficulties and threats can be labelled as fraud issues generated by callers who use highly impersonated telephony numbers, which are faked by certain legal or illegal measures, to allure the callee. However, in spite of the new threats and difficulties, some new opportunities have also arisen to counter spoofed calls, since particular technical measures can be implemented in the IMS network.

The objective of this Supplement to Recommendation ITU-T X.1245 is to analyse the threats and to recommend technical measures and mechanisms to counter spoofed calls in the terminating network of voice over long term evolution (VoLTE) if the identity of the incoming calls cannot be trusted securely by the terminating network. This Supplement focuses mainly on the protection of the VoLTE users, to prevent them from the risk of receiving spoofed calls or to warn them in advance of suspicious spoofed calls by deploying procedures both on the network side and the user side (smartphone), after having conducted a threat analysis of spoofed calls.