Methods, apparatuses, system and computer program product for supporting legacy P-CSCF to indicate the S-CSCF to skip authentication

摘要

It is disclosed a method including transmitting, after successful registration of a terminal at a network entity, a registration message including terminal identity information and integrity indication information indicating affirmative integrity of the terminal identity information; and a method including processing, after reception of the registration message, the received registration message based on the terminal identity information and the integrity indication information such that, i) if the integrity is indicated affirmative, an authentication procedure of the terminal is skipped, or, ii) if the integrity is indicated negative, the received registration message is rejected without provisioning of key information related to registration of the terminal.