Re: Few points
"I upgraded straight away to the full 80Mb/s service. At first, I was getting 76Mb/s. Now, I'm getting 55Mb/s"
This is likely to be caused by the automatic tuning of your connection - as bit error rates (BER) increase (typically due to either weather extremes affecting cabling in the ground or interference/crosstalk from other households in your street), the speed is dropped.
It is unlikely to drop below 55Mbps due to the minimum speed guarantee as engineers will likely carry out a health check on the FTTC cabinet to determine the cause if it is affecting multiple premises.
My personal experience was that I needed a quality VDSL2 router connected directly to a master socket at the point of building entry to get 80Mbps as the existing internal Cat4 cabling run to the master socket was affected by power cabling and even this dropped over time to 76Mbps due to BER spikes.
Biting the hand that feeds IT
