Widely deployed multimedia services are expected to accommodate clients in a highly heterogeneous environment. Clients of a multimedia service may vary greatly in processing and communication capabilities. In addition, due to workload, location, and service time differences, the availability of end-to-end resources between a client and a server may also vary.Current solutions tend to focus on either the qualitative heterogeneity (in client and resource types) or the quantitative heterogeneity (in resource availability) problem. In this paper, we present a framework for dynamic end-to-end multimedia service configuration and reservation - an integrated solution to both aspects of the heterogeneity problem.Service configuration is responsible for choosing appropriate service components to compose a customized service delivery to each client; while service reservation is responsible for reserving the end-to-end resources in a coordinated manner, and providing the best possible quality within the chosen configuration. We have implemented a prototype of this framework as part of the 2K operating system, and tested it by building a proof-of-concept video streaming service on top of it. Our experiments show the soundness of this framework.