On 3 Feb 2026, at 15:18, Martin Passard <martin.passard@ielo.net> wrote: [..] We do have seen other network resetting DSCP fields to 0 and other QoS parameters of trafic they do transport.
Cross-ISP / "Internet" QoS does not exist. Only if you would agree with another network what the meaning of the bits are, could it maybe make sense, but in general it does not, as the whole path has to agree and be provisioned for it. Hence, one should either ignore those markings, and all equipment that those packets passes should then ignore it) or zero them out, and possibly even outbound strip them. Ignoring is the easier way. With the last decade move to more privacy, QoS has started to make even less sense as it should not be known what is inside the packet. Though SSH actually is one of the tools that sets it: https://undeadly.org/cgi?action=article;sid=20250818113047 The situations for the need of QoS are primarily related to oversubscribed links, in that situation one has a bigger issue already: upgrade the links instead. One thing one should be looking at though is Buffer Bloat https://www.bufferbloat.net/projects/ Read the many pages on there, or the many presentations that Dave Täht (RIP!) have given over the last decades. Regards, Jeroen