Fraunhofer develops automotive TCP/IP protocol stack tests

February 22, 2013 // By Christoph Hammerschmidt
With Ethernet around the corner as a standard for in-vehicle data communication, safety aspects become a topic for data transport over this bus. Engineers at the Fraunhofer ESK have developed ways to test the functional behaviour of TCP/IP protocol stacks in vehicles.

The tests developed by Fraunhofer reveal malfunctions and provide hints to OEMs and tier ones about how they can improve their products. The tests also cover IPv6 and Autosar-specific interfaces.

TCP/IP development in the automotive realm currently is driven by three factors: First, the interconnectivity between electric vehicles and charging stations. In this environment, ISO 15118 stipulates the use of IPv6. The second factor is the access to the vehicles for technical diagnosis. In this application field, ISO 13400 mandates TCP/IP and Ethernet for data communications. The third factor is the increasing roll-out of Autosar software in vehicles. Beginning with release 4.1 Autosar also recommends and supports Ethernet and TCP/IP for the communication between ECUs. These factors caused the Fraunhofer engineers to develop automated test procedures for the functional behaviour of TCP/IP stacks in vehicles. The tests can be repeated as often as desired and thus are a reliable basis for automotive designers to secure the communication behaviour of embedded systems. In contrast to available test suites, the Fraunhofer software covers IPv6 and it contains additional tests focusing on the needs of the automotive industry including the TCP/IP test for Autosar environments. In particular commercially available tests for IPv6 still are rare.

In addition. carmakers need absolute reliability in all functions including data communications. For this reason, they request checking all communications functions defined in the RFCs. To cover this request, Fraunhofer has developed about 300 additional tests. Examples are tests for the IPv6 Addressing Architecture according to RFC4291, Dynamic Configuration of IPv4 Link-Local addresses (RFC3927) and TCP Congestion Control (RFC5681).

The current Autosar release 4.1 for the first time defines the usage of the TCP/IP protocol for communication processes between control units in the vehicle. Since the protocol stack has to be implemented for the automotive ECUs for the first time, tests are needed. Fraunhofer developed a test software that facilitates handling Autosar requirements such as non-blocking operation and