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Speed dropping recently - is our SNR ok?

Posts: 1
Registered: ‎24-01-2018

Speed dropping recently - is our SNR ok?

Hi, we've started getting very slow speeds at work recently, (fixed by rebooting the router).

I wondered if our SNR is low and that's part of the problem?

I've attached a snapshot from our DrayTek Vigor 2860 - it looks like downstream SNR is 3 dB?



-Mat Draper

Posts: 11,526
Thanks: 5,129
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Registered: ‎30-06-2016

Re: Speed dropping recently - is our SNR ok?

Welcome to the forum. First of all your router stats are showing that you have a 80/20 service so this should have been posted on the fibre board EXCEPT you also say that this is a 'work' connection, which probably means you have a business account so this should be on the Business board? Which? I have no idea!

Anyway let's address the SNR question. A low SNR under these circumstances generally means that the DLM in your fibre cabinet has reduced the SNR to maximise your speed, hence the 80Mbps speed being reported. If interference was detected that caused excessive transmission errors on your line then the DLM would automatically increase the SNR. The effect of this would be that the detected transmission errors would decrease, as would the sync speed.

If you're detecting slow download speeds then that's a different problem.


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Registered: ‎06-04-2007

Re: Speed dropping recently - is our SNR ok?

Moderator's note by Mike (Mav): This thread is now in the appropriate board.

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Registered: ‎21-04-2017

Re: Speed dropping recently - is our SNR ok?

Hi Mat.

Our tests are showing your router in sync at 80mbps. An SNR of 3db means that your line is pushing as much speed as it can to your router which is likely the reason why your router is in sync at the highest speed possible for FTTC.


Can you run a BT speedtest at using a wired connection, completing the further diagnostics at the end? This will store the result on the supplier system and will help us in reporting a fault to our suppliers.

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