I have a problem at the moment with my BT Ultrafast (G.Fast) service. I had to de-power several times a couple of weeks ago due to electrical work & my broadband speed has dropped substantially as a result. Using the advanced line checker it says there's no problem as my line profile is max=253Mb & I'm getting 242Mb download, however before the power-downs I was connecting at the full 330/50mb capped speed. (The engineer who installed it said my line test showed a theoretical max download speed of over 450Mb) Strangely it only took 3 days for my upload speed to improve, it's now back from 38Mb to 44Mb, but it's been 2 weeks & the download speed has stubbornly failed to increase. Does G.Fast use a DLM? Should I just wait for another couple of weeks before complaining & is there a dedicated technical support phone number for Ultrafast?