Modern day user applications leverages new communication technologies such as WebRTC, WebEx, and Jabber allow devices to connect and exchange media content including audio streams, video streams, and data stream/channels. The present disclosure describes mechanisms for a Port Control Protocol (PCP) server to provide feedback to PCP clients to enforce certain policies on the transport of such media content for a network. A policy may include a traffic handling policy for enforcing differentiated quality of service characteristics for different types of media streams. Another policy may include a security policy ensuring a data files being transmitted over a data channel from one endpoint travels to a security application via a relay element before the packets reaches another endpoint. The mechanisms are transparent to the endpoints, and advantageously preserve the user experience for these user applications.