—Current multimedia application deployment tends to rely on composable service systems, where a complex multimedia service can be composed dynamically from multiple simpler ones distributed widely in the Internet. Related to such a scenario is the problem of finding efficient service paths that meet end-to-end requirements. Work has been done in discovering unicast service paths. However, considering that resources are limited, for distributed multimedia applications that may have a single sender but multiple heterogeneous end-users, it is demanding to build service trees to minimize resource usages by means of sharing. We present a resource- and quality-aware application-level multicast Service Path Finding protocol (mc-SPF¢ ) that constructs, for each application, a more economical service tree instead of independent service paths. Bandwidth and proxy machine resource savings can be achieved by applying the application-layer multicast concept to deliver data through the service ...