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MOST was able to handle most of these use cases in the past. While for premium Audio transport MOST was really well suited, for other use cases like ADAS and AD, MOST was never a preferred solution. Automotive Ethernet in contrast can handle all different use cases in vehicles. More than 10 years ago, OEMs started to reduce the usage of MOST, while they were adding Automotive Ethernet. For many well-known brands and OEMs, Automotive Ethernet has already successfully replaced MOST as well as other technologies.

To the best of our knowledge, OPC UA is not used in cars but has been considered at for other types of vehicles

SecOC is an AUTOSAR standard that defines how to protect messages (partially). SecOC can theoretically protect Signal-based messages as well as SOME/IP payloads. However, SecOC has some shortcomings. For examples the SecOC standard defines no key exchange, SecOC does not support protecting all protocol layers (e.g., IP, TCP, …), and the performance of SecOC implementations is limited. MACsec in contrast has a different approach as it was designed for being part of layer 2; thus, MACsec is able to protect all messages and all protocols. MACsec was designed to be implemented in Hardware, so the performance of MACsec is basically line speed without an overhead for the processor. Summary: SecOC was designed for slow CAN buses that don’t use protocols stacks. MACsec was designed for high-speed Ethernet networks that do. You should use SecOC for CAN messages being transported on Ethernet as well, while MACsec should be added to every Ethernet link.

Go to automotive-macsec.com/ for further information.

KPIT is the leading independent software development and integration company in the automotive industry and Technica Engineering offers leading expertise in E/E Architectures, Automotive Ethernet, MACsec, and other aspects. As SDV needs a strong technology foundation (e.g., communication technology). With KPIT and Technica Engineering joining forces, we are confident that together we can speed up SDV programs of leading OEMs worldwide.

You might be able to create such a demo yourself. Just use two “ECUs” and add some unprotected communication. For example a SOME/IP message for the vehicle speed signal. Now add a man-in-the-middle attacker to change messages; e.g., limiting the vehicle speed to a low value. When turning on MACsec, you will see that the hacked messages are not accepted by the original receiver anymore.

Symmetry is essential for unshielded Ethernet. The cable must meet this symmetry requirement in its construction. The impedance must also correspond to the nominal value to prevent reflections of the signal.

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Dear ke calvin, thank you very much for your message. Yes, gPTP is a Layer 2 protocol. Some other protocols like IEEE 1722 is Layer 2 as well. But protocols like SOME/IP and NM are not on Layer 2. If you've further questions, you can contact us anytime!

thank you for your feedback

Thank you Anil for the question! Sorry for the late reply. This is indeed something interesting. Let us look into the topic and how we can answer this.

Hi Khalid KM! First of all, thank you for your question! 1. In this demo Capture Module Ethernet Combo is the gPTP Grand Master. However any Capture Module or Enhanced Ethernet Switch can be configured as the gPTP Grand Master, depending on the requirement of your use-case. 2. TECMP is an open protocol, made by Technica but is not proprietary and is open to use by anyone. It is available on GitHub. PLP is a vendor specific protocol. 3. The answer is more complex then just yes/no. For simplicity let’s say Capture Modules are capable of handling MACsec traffic. We are preparing special tools for MACsec testing. For more details and discussion on this topic, we would recommend you to approach us on technicalsales@technica-engineering.de so we can discuss the topic further in detail. Best regards Danyal Popalzai

Hello Satheesh Kini! Thank you for your question! I am not sure I understand it correctly but it seems to suggest that 100BASE-T1 does not use a Data Scrambler? In my humble opinion this is not the case. If you take a look at IEEE 802.3-2018 figure 96-8 you can see that a Data Scrambler is part of the 100BASE-T1 PCS right after the 4B/3B conversion and before the 3B/2T. For a good description you might want to also consider "Matheus; Königseder: Automotive Ethernet 3rd Edition", page 159 and following. Best regards, Dr. Lars Völker

@@technica-engineering Thank you for the reply. I was asking more from a point of how synchronisation is achieved in 100 Base T1 if data is all 0s or 1s are transmitted since it's NRZ protocol. I understand 4B/5B encoding ensures there are no consecutive bits continuously while 3B/2T as it seems not the case for consecutive 0s and 1s.

Hey @@KinzRulz, Yes, using 3B2T does not guarantee that the clock is constantly available. This is the same as for 1000BASE-T on which 100BASE-T1 was based and in contrast to 100BASE-TX. For 1000BASE-T and 100BASE-T1, the master generates the clock. In the first phase of the link training the slave synchronize to this clock. In addition, the master determines the phase of the slaves signal in the second phase of link training. Later during transmission, the much long scrambler sequence compared to 100BASE-TX helps that signals basically change often enough. And of course the start and end of the data is marked with specially 00 symbols. Best regards, Dr. Lars Völker

@@KinzRulz You can have a large run of identical symbols in a row. However on average the DC content is zero, so over long term there are transitions. This is exactly why the scrambler is in place so that you have transitions available. The actual RX PMA implemenation is vendor specific. Essentially there is a CDR that tracks the datastream and recoveres a clock based on the data input. For that you dont rely on an edge per symbol, just on a reasonable numer of edges on average. Another effect caused by a run of symbol is BLW which essentially shifts the slicer point based on the history. So the receiver needs to keep track of what has been received in order to know where the slicer level is. If you google for baseline wander you will find a bit of background.

@@paxer Thank you. I will search on mentioned topics.