Hello, I have reviewed this document as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG. These comments were written primarily for the benefit of the security area directors. Document editors and WG chairs should treat these comments just like any other last call comments. The summary of the review is ready with issues. This draft describes an architecture for deterministic networking that provides for delivery of packet flows with low packet loss and with a maximum amount of latency. A nit first. The terminology seems a bit overblown. We have DetNet Intermediate nodes that could be relay nodes or transit nodes; and a DetNet system that is a DetNet aware system or transit node or relay node; and DetNet edge nodes that are relay nodes; and DetNet relay nodes that can be bridges, firewalls, or anything else that participates in DetNet. Finally, to translate between 802.1 TSN and DetNet we have a "relay system" that is an 802.1 term for a DetNet intermediate node which, as we have seen, is a DetNet relay node. This can be simplified considerably. The Security Considerations is thin, especially for an architecture draft that is going to be referred to by subsequent drafts which will just say something along the lines of, "as an instance of the DetNet FooBar, these Security Considerations are those from [ARCH]", where ARCH is the RFC that comes out of this I-D. I think there needs to be a description of the various points in the architecture that an attacker could exploit, and if a point is not exploitable it should say so. For instance: - is it possible for an attacker to launch a DoS attack by manipulating member flows of a DetNet flow in order to force DetNet nodes to consume buffers they allocated to deal with the DetNet flow? - If an end system is not DetNet aware there needs to be a DetNet edge node to handle the encaps of the flow into the DetNet system. Can an attacker in that case introduce packets that shouldn't be part of the DetNet flow into the flow by getting the edge node to encaps them as such? If there are any assumptions being made-- e.g. "insider attacks are not being considered"-- they should be mentioned. regards, Dan.