ISO-TP is an international standard for a transport protocol for CAN-based bus systems. The ISO-TP functions on OSI layers 3 and 4 and can transport up to 4095 bytes of user data per telegram. ISO-TP segments the data bytes into several frames and adds metadata to the data packets, which enables the recipient to interpret the individual frames.
With CAN FD and the higher payload of 64 bytes per CAN frame, ISO 15765-2 has been extended to the effect that segmented messages up to 4 gigabytes long can be transmitted with this standard. However, due to the comparatively low data rates of the CAN, this is not completely called up in practice.