If I bought the 76bps package but was only receiving around 40mbps. What would an engineer do to increase that speed to the 76mbps?
Would the engineer change something in the green box?
if you currently can only get 40mb and unless your attainable speed shown in hub stats is far higher than 55mb then moving to fibre 2 will not help your speed moving to fibre 2 just removes the 55mb cap and moves it to 80mb but you only see benefit if your line is capable of faster
enter your phone number and post results
https://www.broadbandchecker.btwholesale.com/#/ADSL
if the engineer was there fixing a fault possible causing connection problems then I would expect that engineer had the DLM reset which would start your connection like new hence speed returned to expected
the engineer came to fix the problem of the internet disconnecting every time the telephone rang. All that was needed was a micro filter to be added but he changed the master socket and my speeds increased to the guaranteed speeds of 76mbps but this has caused issues with online gaming so I'm trying to figure out what exactly has been done and see if it can be reversed as my gaming is awful now whereas before the engineer visit it was exceptional.
all the disconnection had resulted in the DLM taking action to stabilise your connection by increasing noise margin and reducing connection speed and in certain circumstances your connection would be put in banded profile
as the engineer solved the problem of disconnections he then had your line reset which got you out of the banding and your speed back to how it should be. there would be no other changes but with DLM reset you need to let connection settle and find what is best for your line
no
all of that is controlled b the DLM automatically are you using an ethernet connection not wifi
https://community.plus.net/t5/Library/FTTC-DLM-What-it-is-How-it-works/ba-p/1322799
DLM is an automatic process, there is nothing anybody can do to change things. It has probably put your line on interleaving which it may change to fastpath after a few days once it has had chance to analyse your line characteristics.