A communication network for transmission of messages at different transmission rates, comprising - a bus line (12', 12"), and - a plurality of bus participants (14, 16) each of which includes a bus transceiver connected to the bus line (12', 12") and a control unit coupled with said bus transceiver, inter alia, for converting messages received via the bus line (12', 12") and for generating messages to be sent via the bus line (12', 12"), - wherein each message includes control data and payload, - wherein the messages include first messages whose payload is transmitted via the bus line (12', 12") at a first rate and second messages whose payload is transmitted via the bus line (12', 12") at a second rate which is higher than the first rate, - wherein the control data of each message contain a coding representing the transmission rate of the payload of the respective message, - wherein the bus participants (14, 16) include first bus participants which can exclusively receive and process a first payload and second bus participants which can receive and process both first and second messages, - wherein the bus line (12', 12") comprises a first and a second bus line section, - wherein the first bus participants are connected to the first bus line section and the second bus participants are connected to the second bus line section (12"), - wherein first messages are adapted to be transmitted both within the first bus line section and within the second bus line section (12") and second messages are exclusively adapted to be transmitted within the second bus line section (12"), and - wherein the two bus line sections (12', 12") are coupled with each other by means of a unidirectional transmission filter for allowing for a transmission of first messages from the first bus line section to the second bus line section (12") and for preventing the transmission of second messages from the second bus line section (12") to the first bus line section. characterized in - that the prevention of the transmission of a second message from the second bus line section (12") to the first bus line section means the prevention of the transmission of a second message to the first bus line section at the second rate, wherein the unidirectional transmission filter, upon detection of the coding indicating the second payload transmission rate when receiving a second message, substitutes the payload of the second message by a substitute payload and transmits this substitute payload at the first rate to the first bus line section. - a bus line (12', 12"), and - a plurality of bus participants (14, 16) each of which includes a bus transceiver connected to the bus line (12', 12") and a control unit coupled with said bus transceiver, inter alia, for converting messages received via the bus line (12', 12") and for generating messages to be sent via the bus line (12', 12"), - wherein each message includes control data and payload, - wherein the messages include first messages whose payload is transmitted via the bus line (12', 12") at a first rate and second messages whose payload is transmitted via the bus line (12', 12") at a second rate which is higher than the first rate, - wherein the control data of each message contain a coding representing the transmission rate of the payload of the respective message, - wherein the bus participants (14, 16) include first bus participants which can exclusively receive and process a first payload and second bus participants which can receive and process both first and second messages, - wherein the bus line (12', 12") comprises a first and a second bus line section, - wherein the first bus participants are connected to the first bus line section and the second bus participants are connected to the second bus line section (12"), - wherein first messages are adapted to be transmitted both within the first bus line section and within the second bus line section (12") and second messages are exclusively adapted to be transmitted within the second bus line section (12"), and - wherein the two bus line sections (12', 12") are coupled with each other by means of a unidirectional transmission filter for allowing for a transmission of first messages from the first bus line section to the second bus line section (12") and for preventing the transmission of second messages from the second bus line section (12") to the first bus line section. - that the prevention of the transmission of a second message from the second bus line section (12") to the first bus line section means the prevention of the transmission of a second message to the first bus line section at the second rate, wherein the unidirectional transmission filter, upon detection of the coding indicating the second payload transmission rate when receiving a second message, substitutes the payload of the second message by a substitute payload and transmits this substitute payload at the first rate to the first bus line section.