To clarify, I seem to remember some time ago that BT needed to upgrade the firmware in order for ECI modems to use G.INP.
You are probably thinking about "issue 1" described on Kitz's forum:
This suggests that the appropriate firmware was available at least early 2015 - and it is likely to continue to be available. It isn't so much that firmware is "sent out"; more that an agent process on the modem goes searching on a regular basis. All BT need to do is to leave the firmware sitting on a download site, available to the agent. All the agent requires is a modem that will sync.
Beyond that, understanding the support for G.INP on ECI modems is something of a grey area. The original/locked modems themselves do not tell us - leaving us to work with supposition, guesswork and trials.
On one side, Batboy (almost exclusively) believes that ECI modems (and the HH5a) do not support G.INP downstream. He regularly tells this forum he has evidence, but forum threads that attempt to explore this evidence regularly degrade into slanging matches.
In this thread, Batboy's position (of not knowing about any firmware for ECI modems) fits with his stated position on G.INP support in general.
On the other side, BT appear to believe that ECI modems support G.INP (downstream, at least), and have done for a long time. They *did* need a firmware upgrade - and "issue 1" (as mentioned at the top of this post) was a proper concern for Openreach engineer visits over a year ago.
Unfortunately, the ECI modems also became embroiled in the screwup with upstream
G.INP (labelled "issue 2" on Kitz's forum
). This helped mask any real capability.
Kitz did get a subsequent, attributed, description of G.INP out of Openreach (available here
). The third question would be the appropriate point for Ian Lawrence to mention any lack of support for G.INP for ECI modems ... but, instead, we get a reference to the SIN confirming that downstream support is mandatory.
For a long time, the "inbetween" position for a lot of "interested observers" was that there was *some* evidence that G.INP was in use for ECI modems, but not in any provable sense.
Now that BT have started the rollout of G.INP activation onto their ECI cabinets, we appear to be seeing ECI modems respond very positively, with good speed gains. Again, the details remain hidden, so there is little provable
, but most of those in-between observers appear to be becoming more comfortable believing that the ECI modems do indeed support G.INP.
If this is indeed the case, there equally does not appear to have been a recent
firmware release for this support - so the firmware that *did* add support is likely to date back to early 2015.
I suspect the only way you'll get an answer is for you to try it ... which you've now done.
The best way to figure the sync speed is to run a BT-Wholesale speedtest, and follow through into the final phase. That will allow you to see the "IP Profile" value, from which an approximate sync speed can be calculated.
That'll let you compare speeds, but it will not tell you much about whether G.INP is active. You'll have to figure out who to believe for yourself.