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Reducing sync speed

First Timer

Hi there,


I'm not sure if this is a tariff issue or a technical one but my maximum sync speed seems to have reduced.


I'm lucky to be very close to the cabinet in my street so looking at my router the attainable speeds are 85664kbps down and 21579kbps up as I look today. I'm on "faster fibre" so looking at that you'd think my sync speeds should be 80/20, which they used to be - 79999 down and 20000 up - bliss.


Recently I noticed my downstream reduced to 73999 when the attainable rate was still above 80000 (I have seen this as high as 96000 but never lower that 85000). I was wondering if there was any reason for this?


I've had a good clear out around my router and unfortunately think I've triggered DLM by restarting it a few too many times. Today my downstream sync speed is 71076 vs a maximum attainable 85664 with a whopping 1085 interleave depth. Actual download speeds are 50Mbps at best. Line stats below.


So really I have two questions:

1/ If I hadn't been messing about yesterday and the line is best-case, why would I only be getting 73999 down when the line is capable of well over 80000?

2/ Is there anything that can be done to remove the limitations and interleaving now in place since this was caused by router changes and nothing is wrong/changed with the line itself?






Screen Shot 2020-05-05 at 11.42.48.png


Community Star
Hi. Please note i do not work for TT
One thing that worked for me a few months ago. Was to do following
Please note that DLM is under BT control and not TalkTalk.
To reset BT's DLM back to highest setting , i powered off the router for 35 to 40 mins. (no less than this time ! )
Then re-applied power to router and let it sign back on. Mine then reverted back to fastest setting. With luck yours will also do this.
You may not always get the speed router informs. Mine can go to 46,000Kbps but i may only connect at say 40,000 Kbps
First Timer

Thanks paulshent, I did what you suggested and powered down for about an hour and a half. Once back up downstream and interleaving were both slightly less, looks like I'll just have to wait.


Screen Shot 2020-05-05 at 17.33.34.png



If someone from TalkTalk could come back on the 74 vs 80 thing that'd be great, thanks.

Community Team - TT Staff

Hi lockdown2020,


I've taken a look at your line and can see the line is currently being capped at 74mbps and your sync speed is 71.1mbps. This could be partly DLM capping the speed due to the reconnections of the router however one of the line tests is indicating a potential fault in the network caused by an earth contact in the copper.


The location is unknown right now but if this is between the cabinet and the premises there's a good chance that this is causing the loss of sync speed so I have arranged for an Openreach engineer to investigate in the next 72 hrs.


Please allow a few days after this for the line to stabilize and let us know if you're still seeing a lower sync speed.




First Timer

Hi Ben, thanks for your reply,


An Openreach engineer did ring and said he could see the line was syncing at 71 and didn't say anything about a ground fault (unfortunately I didn't see your message until after). He just advised to wait, which I have done and the line has returned to 'normal' syncing at 73993 with no interleaving.


Screen Shot 2020-05-07 at 13.58.30.png

Can you elaborate on the cap of 74 you mention, ie where it's come from and whether it can be removed?





Community Team - TT Staff

Hi Alex,


I'm sorry for the delay. Can I just confirm, what are your current throughput speeds at the moment? Is the overall performance of the connection ok?