With ever more complex multimedia applications used in mobile devices, the realization of high performance, flexibility and programmability requirements depends largely on the design of a system communication infrastructure. This infrastructure, often a network, should provide a large variety of services for the transportation of streamed data. When an external memory is also used for streaming communication purposes and, together with the communication infrastructure, forms a part of the streaming, additional support is needed for the memory in order to guarantee the integrity of the communication services provided by the network when data is accessing the memory. This led us to a design of a streaming memory controller (SMC) for off-chip (DDR-)SDRAM memories that enables a shared memory implementation of the streaming based on an off-chip network (PCI Express). In this paper, we present the ideas that gave rise to the SMC, the actual design of the SMC, as well as the evaluation of the design.