looks at Japan, UK (OpenReach), and a lot of other places still using PPPoE (on fiber!) for complicated reasons
Some of those (including many providers on Openreach) will support mini-jumbo frames that allow an MTU of 1500 inside pppoe.
alt Hacker News
Some of those (including many providers on Openreach) will support mini-jumbo frames that allow an MTU of 1500 inside pppoe.