A media flow bridging device includes a control module for receiving control message, performing media negotiation and controlling service process; and an RTP module connected with the control module, for processing RTP protocols and transferring media flows. A system for media service includes: a control device for processing signaling and controlling service process; a media resource device connected with the control device, for providing media resource; and a media flow bridging device connected with the control device and the media resource device, wherein the media resource device transfers media flow to or from a device exterior to the system via the media flow bridging device. The invention can achieve functions such as operator quality control, automatic manual service switch, automatic service switch and etc. in a broadband network if media flows are exchanged between a user terminal and a resource device point-to-point through RTP directly in the broadband network.