In a way, yes the IP Profile
could have dropped because of the retrains. It sounds that the person you spoke to has some training but not sufficient to explain the fairly complex mechanism over the phone. That isn't surprising for front-line support at a large ISP.
Having said that, the capping due to over-subscription at the cabinet is utter tripe.
It isn't the IP Profile itself that is the problem. That is calculated as a percentage (96.79%) of the connection/sync speed, which with the ECI modem that Openreach gave given you can't be seen in any simple way.
What will have happened is that the DLM
in the cabinet will have intervened, altering the line parameters to stop the disconnections. It doesn't know they were because of power faults that have been fixed.
With luck all that has happened is that it has introduced Interleaving
and raised the noise margin
. Both of which lower the sync. The good news is that after a few weeks of stability both of these will be returned to normal.
Because that return is automatic it is very rare for any ISP to arrange for it to be done manually. If you were down at 5Mbps maybe it would be easier.
However, a system called banding
may also have been applied. That generally did, and I think still does, need an engineer visit who then requests a reset once convinced you haven't got a problem that would cause it to be re-applied by the system. It sets a maximum and minimum speed for the connection. There is this table
but I believe it may be out of date
. I can't really tell you much more about that.
If you haven't done so you should post about this problem in the fibre section of the Plusnet Community forums
and/or in the Plusnet forum here. The Community one is likely to get a quicker response from the higher level support staff that monitor it more regularly than the one here, (though I think they are basically Mon-Fri staff. Some certainly do sometimes look in at weekends). The are generally excellent and will be able to check if it is just the interleaving and noise margin such, or if it is banding. I'm sure they will sort it out if it's the latter.
It would be a shame if you left over this. As long as you do get sensible results from them.
My broadband basic info/help site - www.robertos.me.uk.
Domains,site and mail hosting - Tsohost
Connection - Plusnet
UnLim Fibre (FTTC). Sync ~ 52.8 (interleaved)/15.0Mbps @ 600m. - IPv4BQM