Update Linux Tips for fq_codel and ECN (ECN being the last part of the puzzle to need widespread enablement).
SACK and DSACK seem to be enabled by default upstream, systemd enables fq_codel by default these days.
Fair comment about TCP option intolerance, I think ECN problem has gone away, e.g. https://www.ietf.org/proceedings/98/slides/slides-98-maprg-tcp-ecn-experience-with-enabling-ecn-on-the-internet-padma-bhooma-00.pdf and also my own experience!.
Note the "" in markup text didn't seem to work nor to exist as wiki pages, so I removed the tags, consistent with other headings.
Update Linux Tips for fq_codel and ECN (ECN being the last part of the puzzle to need widespread enablement). SACK and DSACK seem to be enabled by default upstream, systemd enables fq_codel by default these days. Fair comment about TCP option intolerance, I think ECN problem has gone away, e.g. https://www.ietf.org/proceedings/98/slides/slides-98-maprg-tcp-ecn-experience-with-enabling-ecn-on-the-internet-padma-bhooma-00.pdf and also my own experience!. Note the "" in markup text didn't seem to work nor to exist as wiki pages, so I removed the tags, consistent with other headings.