I am within a mile of my local adsl max enabled exchange and for most of the day get a download speed of 6,5 Mbps,. In the evening I quite often find that the line gets very sluggish and I am down to between 0.9Mbps and 2Mbps as measured on a number of Speedtesters including the one on this site. Line stats remain the same. However when I try the BT Speedtest it always shows figures between 5.5Mbps and 6.7Mbps. Does this suggest that the problem I am experiencing results from my ISP routing/congetsion rather than line problems. There are no reports of my exchange having congestion issues.
I would appreciate any advice on this before taking this further with my ISP.