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Sudden sync speed drop

Message 7 of 7

For some background: connected with BT FTTC around 6 years ago. The was no way to look at the modem stats back then, but the speedtests gave me a straight 80mb/s. Speed was entirely stable for about 2 years, then began to slowly drop. By the time I left BT and joined TT about 30 months ago, the sync was around 62mb/s.


Over the past year (approximately), the speed has dropped to about 52mb/s with an upload of around 15mb/s. I am using the latest TT router with the single white LED on the front.


The router FW was upgraded I guess a few months ago with a version of xxxx2800t. This has been stable with 52mb/s down (sync of about 57mb/s), with a SNR always around 6dB, and upload close to 15mb/s.


This last week, I have noticed a FW upgrade to xxxx2808t and a resulting SNR of about 3dB, but still at 52/15.


I had to switch the power off for the house yesterday, and when I switched it all back on, the router SNR returned to 6dB, but now with a line rate of 47mb/s and a sync of 41.7mb/s. The upstream is now 12.8mb/s.


So to summarise, new firmware was installed and as far as I can tell, the SNR went to 3dB around the same time (possibly coincidence). Since restarting the router, the SNR has returned to 6dB and I have lost aboput 9mb/s of downstream and 2mb/s of upstream.


The connection is now give or take at half of its initial speed when connected several years ago, and I know that capacity was reached for the cabinet (as is still at capacity now) just after I joined TT, so no new connections in some time.


We're also at a point now where the speed boost I'm paying for is largely redundant.





Message 1 of 7



Thanks for confirming this. It would be worth ruling out any noise on the line as this can affect the broadband connection. Please let us know how you get on.





Message 2 of 7

I may be able to hear some noises on the line, though it's an older cordless phone so it may be that. I shall dig the simple corded phone I have out tomorrow and plug in to check.


There is only one socket on the system, which is an NTE5c to which the router is directly connected. No extension sockets.


Message 3 of 7

Hi numbskull,


Thanks for the update. Can you hear any noise on the voice service such as crackle/hiss/buzz,etc? If the master socket does have a test socket then would it be possible to connect your router directly at the test socket for at least 48hrs so we can see how the connection stats compare in this set up?





Message 4 of 7

Thanks for the reply. Having looked at the router connection information, I can see what is happening.


For some time (months, possibly more than a year), the connection has maintained a sync of about 52mb at a SNR of 6dB. Recently, there has clearly been noise on the line as when synced at this speed, the SNR drops to 3dB.


Therefore, if I reboot the router when the line is "at" 3dB, it attempts to reconnect with it's 6dB profile, and lowers the connection speed by about 9mb to do this.


I saved this information of the connection statistics whilst refreshing the router page. This happened over a period of about 12 minutes on 27/12/2019:


Time     Max Rate     Actual Rate     Noise Margin (dB)

11:50    57726          50644              2.6

11:51    57726          50644              6.3

11:53    57726          50644              3.0

11:58    57726          50644              6.2

12:00    57726          50644              3.1

12:02    57726          50644              3.0


When I restarted the router when possibly trying to negotiate noise on the line, I get:


Max Rate     Actual Rate     Noise Margin (dB)

47363          41777              6.2


The attenuation figure remained at 19dB throughout. Any thoughts?


Message 5 of 7

Good Morning,


I'm sorry for the delay in getting back to you. Unfortunately it's not possible to roll the firmware back to a previous version. I've run a test on the line which hasn't detected a fault. Does your master socket have a test socket? Is the voice service also ok with no noise on the line?





Message 6 of 7

Perhaps someone at TT could push 2800 FW to the router to see if there's an issue there?