A protocol converter, PC, comprising: a session request receiving unit, configured to receive a first session request sent by a third party application function, AF, wherein the first session request comprises identity information of the third party AF and identity information of a policy and charging rules function, PCRF, entity in a network; a first session establishing unit, configured to establish a first session with the third party AF; a request sending unit, configured to send a second session request to the PCRF entity in the network, wherein the second session request comprises identity information of the PC and the identity information of the third party AF; a second session establishing unit, configured to establish a second session with the PCRF entity in the network; an information receiving unit, configured to receive information reported by the PCRF entity in the network, wherein the information comprises a reported event and identity information of the third party AF; and a forwarding unit, configured to forward the reported event to the corresponding third party AF according to the identity information of the third party AF, wherein the identity information of the third party AF is comprised in the information reported by the PCRF entity, wherein the identity information of the PCRF entity in the network comprises identity information of a user equipment, and the PC is configured to determine an identity of the PCRF entity according to the received identity information of the user equipment and a pre-configured correspondence between the identity information of the user equipment and the identity of the PCRF entity in the PC. a session request receiving unit, configured to receive a first session request sent by a third party application function, AF, wherein the first session request comprises identity information of the third party AF and identity information of a policy and charging rules function, PCRF, entity in a network; a first session establishing unit, configured to establish a first session with the third party AF; a request sending unit, configured to send a second session request to the PCRF entity in the network, wherein the second session request comprises identity information of the PC and the identity information of the third party AF; a second session establishing unit, configured to establish a second session with the PCRF entity in the network; an information receiving unit, configured to receive information reported by the PCRF entity in the network, wherein the information comprises a reported event and identity information of the third party AF; and a forwarding unit, configured to forward the reported event to the corresponding third party AF according to the identity information of the third party AF, wherein the identity information of the third party AF is comprised in the information reported by the PCRF entity, wherein the identity information of the PCRF entity in the network comprises identity information of a user equipment, and the PC is configured to determine an identity of the PCRF entity according to the received identity information of the user equipment and a pre-configured correspondence between the identity information of the user equipment and the identity of the PCRF entity in the PC.