The transmission of messages with CAN is based on the "producer-consumer principle". A message transmitted by a producer node can be received by all other consumer nodes. For this, messages are not marked by a destination address but instead by an unambiguous "message identifier". The transmission of messages to all nodes of a network is also referred to as "broadcasting". In the CAN protocol, messages usually have an 11-bit long identifier (standard format). This means that 2048 different messages per system can be defined. This number is more than sufficient in most applications. However, for special applications (e.g. heavy duty vehicles) the use of 29-bit long identifiers (extended format) and thus the definition of up to 512 million different messages is also possible. A node must filter the messages which are relevant for it from the message stream on the bus.