The D8B comes standard with a 10 base-T ethernet port, which can be used to "cascade" two or more D8B's together. This links the D8B's controls like fader bank switching, solo logic, auxiliary selection, and cue controls. All signal routing is done through the ALT I/O slots, which allows you to bus eight channels of signals (which can be the auxiliaries, sub busses, or the master L-R mix) from each cascaded console back to the master desk. Two D8B's cascaded together give you 48 dedicated analog inputs, 48 digital inputs, and 8 channels of auxiliary or sub bussing from the slave to the master D8B.