A method of disconnecting a packet data network (PDN) connection or a packet data protocol (PDP) connection from an access point name (APN) by a user equipment (UE), including sending, to a network apparatus, a signaling message to request disconnecting the PDN connection or the PDP connection from the APN, wherein the signaling message includes an information element (IE), and receiving a deactivate request message from the network apparatus which deactivates the PDN connection or the PDP connection, in response to the signaling message.