In association with a virtual area, a first network connection is established with a first network node present in the virtual area and a second network connection is established with a second network node present in the virtual area. Based on stream routing instructions, a stream router is created between the first network node and the second network node. The stream router includes a directed graph of processing elements operable to receive network data, process the received network data, and output the processed network data. On the first network connection, an input data stream derived from output data generated by the first network node is received in association with the virtual area. The input data stream is processed through the stream router to produce an output data stream. On the second network connection, the output data stream is sent to the second network node.