FIELD: physics, communications.
SUBSTANCE: invention discloses a method and a device for filtering an identifier for establishing a connection with a busy subscriber originating from a malicious user and a calling side network device for realising the method. The invention relates to executing a service for establishing a connection with a busy subscriber. The method of filtering an identifier for establishing a connection with a busy subscriber from a malicious user comprises steps of: when the calling side network device determines that the call request bears an identifier for establishing a connection with a busy subscriber, rejecting the current call request or deleting the identifier for establishing a connection with a busy subscriber from the call request, and then forwarding the call request. The device for filtering said identifier includes a receiving unit, a detecting unit, a deleting unit and a forwarding unit. The calling side network device includes a receiving unit, a detecting unit and a rejecting unit.
EFFECT: filtering an identifier for establishing a connection with a busy subscriber originating from a malicious user, avoiding extraordinary access to a called subscriber by malicious subscribers.
8 cl, 8 dwg
