Protocol architecture for wiring media streams and specifying mixing behavior in a multipoint control unit. The protocol provides the capability to expose the core mixing algorithms to modification for mixing media without dealing with the functionality of the mixer itself (e.g., ports and IP specifics). The protocol facilitates the wiring of input media streams to output media streams by changing the mixing behavior via changes to the mixing algorithms using the protocol. The protocol operates based on a schema that includes controls related to route, wire, and filter for the mixer input and mixer output.