A system offering an Application Programming Interface for multi-stream multimedia applications running on at least two registered end peers participating in a mobile telecommunication session and/or middleware being connected to a mobile network. The system providing guaranteed end-to-end quality and resource capabilities using the concept of concatenated E2ENP phases and providing a pre-negotiation of a multiplicity of alternative capabilities and QoS Contracts, management of leased pre-negotiated information, session establishment between said end peers with negotiation of a multiplicity of alternative capabilities and/or QoS Contracts, and a dynamic re-negotiation of the end-to-end quality and capabilities. The information to be negotiated is expressed in an interchangeable format allowing multi-stream multimedia applications to agree on a specific reference model of the negotiated information, which can then be used for dynamically configuring Finite State Machines to orchestrate local, peer, and network resources according to the preferences and profiles of the respective user.