A communication system (2000) is disclosed. One embodiment includes at least two functional blocks, wherein a first functional block (1002) communicates with a second functional block (1008) by establishing a connection, wherein the connection is a logical state in which data may pass between the first functional block (1002) and the second functional block (1008). Another embodiment includes a bus coupled to each of the functional blocks and configured to carry a plurality of signals. The plurality of signals includes a connection identifier that indicates a particular connection that a data transfer is part of, and a thread identifier that indicates a transaction stream that the data transfer is part of.