The invention relates to a communication system having a communication bus, a master device, which is connected to the communication bus and which communicates with the communication bus in a master mode, and several slave devices which can be connected to the communication bus and which communicate with the communication bus in a slave mode. To improve the performance capability of the communication system, the slave devices can be connected to the communication bus using a communication module designed as a proxy, wherein the communication module is connected to the communication bus using an input port and output ports for connecting the slave devices using a point-to-point connection, the communication module has a communication processor connected on the input side to the communication bus and on the output side to a first internal bus by means of a first serial interface.