In next generation networks (NGN) architecture which is standardized in ITU-T, Ri interface is defined as the interdomain QoS control interface between Resource Admission and Control Function (RACF). By the coordination of NGN operators using Ri interface, it is expected that more users can obtain high quality network services. However, neither the design of functional architecture for inter-domain QoS control of RACF nor the control sequence of Ri interface are provided so far. In this paper, a session-based resource management capability for inter-domain QoS control is demonstrated for the first time. For a video-on-demand application, the extended RACF is applied and the resource reservation over different NGN-domains is successfully conducted.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.