-- Future distributed applications are expected to be deployed in an environment that is more dynamic and heterogeneous than ever before. The environment features are difficult to predict beforehand due to their variations. To cope with such variations, it is important that the protocol stack is adaptable to changing requirements. This paper proposes a component-based Dynamical Protocol Framework (DPF) for multimedia applications. DPF dynamically builds an adaptive protocol stack by automatic discovery of protocol components and runtime configuration/reconfiguration of the protocol stack. Performance measurement shows that compared with directly using interfaces provided by JMF, using DPF to set up a dynamic protocol stack incurs slight overhead in unicast, and a similar condition is observed in multicast. This is the trade-off for the abilities to configure and reconfigure protocol stack during stream set-up and run time. Keywords -- dynamic protocol stack; multimedia; adaptive middle...