This is not unlike animals with layered nervous systems. Notice also that the upper layers of the subsumption architecture don t preclude the possibility of higher-level intelligence. Computation consists of asynchronous networks of AFSMs. There s a fixed topology of connections between AFSMs. Any communication path must be made quite explicit by specifying a wire.
Processing is distributed making a central world model difficult to achieve.
Numeric messages are sent over connections, arriving at input ports. The meaning of messages depends upon the purpose of sender and receiver. Sensors and actuators are directly connected to network.