1. A method of managing a mobile network, the method comprising:obtaining, by a session management function (SMF), a trigger to release a packet data unit (PDU) session;
sending, by the SMF, a session release request to a user plane function (UPF), the session release request including an identifier of the PDU session to be released and requesting the UPF to drop all remaining packets of the PDU session and release contexts associated with the PDU session;
receiving, by the UPF from the SMF, the session release request;
dropping, by the UPF, all remaining packets of the PDU session and releasing said contexts associated with the PDU session; and
sending to the SMF by the UPF a response indicating an acknowledgement of the session release request.