I'm back, and have proper access to stats, so will take a look at @NS's stats with a bit more rigour later. This thread has moved on somewhat, so there's a lot to catch up on.
In the meantime, can I just point out that:
a) "IP profile" is a term used by BT wholesale that is used to distinguish between the raw throughput of a line, from the encapsulated "IP date" rate carried in amongst the framing overhead.
b) Framing overhead represents the overhead bytes that surround the IP packets when sent across VDSL2; Some are visible and subtracted from the sync speed (such as the PPPoE framing bytes), while some are less visible, and subtracted before the sync speed is calculated (such as the FEC overhead); My work before the holiday was to figure where the framing overheads for the G.INP DPUs fell within this.
All ISP's (including BT Wholesale) encounter some form of framing overhead, of both types, across the Openreach FTTC product - it is inescapable. Dray's number show that an overhead exists for Sky as much as anyone else.
However, it remains only BT Wholesale that give this overhead a name - IP profile - and then sets rules about what the ISP must do with that information.
Perhaps both Sky and TT have a name, and rules, but they aren't publicised.
