Hi all,
I have had Infinity since July 2011 and am about 1km from the PCP (as the road wiggles). From the start I got download speeds of about 36-37Mb/s (improved slightly earlier this year, presumably due to the VDSL2 profile change), with an IP profile well above this (don’t remember the exact number). I have never attempted to access the modem stats, since these speeds seemed good for the length of line and the line seemed stable.
Recently I noticed that download speeds had dropped slightly, to about 34-35Mb/s. I then found that the BT Speedtester was reporting that my IP profile was now 35.73Mb/s, so the speed was being limited by the profile, rather than having some headroom as before.
I was not particularly concerned, since network congestion is often the limiting factor anyway, and the difference was hardly noticeable in practice. Nevertheless, out of curiosity, I decided to try rebooting the modem, which had been powered continuously since it was installed under the OR exchange programme some months ago. I powered it down for about half an hour this morning, and – lo and behold! Afterwards the IP profile had increased to 38.71Mb/s and download speeds were back to 37-ish. This evening I rebooted the modem again, this time using the reset switch, to check if higher noise levels after dark would cause a lower sync speed, but the profile and speeds have remained the same.
When previously on ADSL Max and later ADSL2+, I was aware that forced re-syncs were sometimes necessary to reduce the SNRM to the target and so get the best out of the line. However, I had read somewhere that the OR FTTC DLM was supposed to be “clever” enough to adjust sync speed on the fly, both down and up, without user intervention. Is this not in fact the case? If not, how many unsuspecting users are making do with unnecessarily slow speeds?