Abstract: The present invention provides a method, system and apparatus for an MG to transmit and receive multicast data. A method for an MG to receive multicast data in embodiments of the present invention include the following: the MG receives a multicast-related indication from the MGC, reports the relevant information to the router in the network at the multicast source side according to the indication, and requests to join the multicast group. The MG receives the multicast data transmitted by the multicast source. A method for an MG to transmit multicast data in embodiments of the present invention include the following: the MG receives the multicast-related indication from the MGC; and the MG transmits the corresponding multicast data to the users in the network at the receiver side in the form of multicast according to the indication.

Abstract: The present invention relates to a method for obtaining Quality of Service (QoS) information of a session. The present invention may obtain QoS information of a session by analyzing a control message of the session on a Media Proxy (MP). The present invention may also make a QoS analysis only on the session which needs the QoS analysis, according to configured policy information, and returns the corresponding QoS analysis result to a Signaling Proxy (SP) or another particular server. Moreover, for the session on which the QoS analysis needs to be made, it may be configured that the QoS analysis is to be made on only parts of the control messages. Therefore, the implementation of the present invention may not only save processing resources of the MP but also increase the efficiency of the QoS analysis for the session during the QoS analyzing and processing procedure.