This invention presents a framework for achieving dynamic End-to End QoS
negotiation and control coordination, with distributed multimedia
applications. The framework builds upon dynamic capability negotiations
and specification of Adaptation Paths and (alternative) QoS Contracts,
based on user preferences. In particular we present a protocol providing
End-to-End negotiation of alternative QoS, capabilities, and
preferences/configurations, based on extensions of IP-based protocols
like SIP/RTSP/SDP, in coordination with mechanisms for network resource
reservation (e.g. RSVP), local terminal resource (e.g. CPU, memory,
power, auxiliary devices) reservation, and adaptation mechanisms. To this
extent, and with respect to two or more peers (101, 103) this invention
identifies six phases, through which said peers can establish multiparty,
multi-stream, multimedia communications. In detail, the phases are:
Protocol Discovery (104), Pre-Negotiation (106), Multi-Stream QoS
Synchronization and QoS Correlation (107), Fast-Negotiation (obeying the
Economy Principle) (108), Re-Negotiation (obeying the Economy Principle)
(109), Resource Reservation Release (110). All the six phases can be
concatenated, or be executed at different times. This invention also
presents the concept of the E2ENP Broker (105), an optional third-party
entity, which can be used for relieving peers (101, 103) from performing
the time- and resource-consuming Pre-Negotiation phase (106) (and
eventually also the Multi-Stream QoS Synchronization and QoS Correlation
(107). This entity may coincide with e.g. audio-/videoconference bridges.