Kitz Forum

Broadband Related => Broadband Hardware => Topic started by: ste91 on May 13, 2022, 03:46:39 PM

Title: new vigor 2866ax snr change
Post by: ste91 on May 13, 2022, 03:46:39 PM
Does anyone know if draytek have stopped allowing snr tweaking on the newer models or is it just a firmware bug?

On my old 2820, I was able to sucessfully lower my snr down to 3db from 6, using the vdsl snr -30 command for a higher sync speed. It does not work on my new 2866ax, I can set at -30 but the snr will stay the same (6db) and no change in sync. 

***edit*** I have tried the lastest firmware from draytek site with no luck, it is still behaving the same! One other thing I have noticed, when I set 'vdsl snr -30' it will resync ok (albeit still with dlm target of 6db), but then if I were to change back using vdsl snr 0, it will not sync again until I reboot the device.
Title: Re: new vigor 2866ax snr change
Post by: Edinburgh_lad on May 14, 2022, 11:24:44 PM
I believe SNR tweaking also depends on whether your DSLAM will allow it like type of profile and condition of the line, but I may be wrong.

For the new SNR value to stay on Drayteks, you also need to 'save' it.

You'll find the following guide helpful: https://www.draytek.com/support/knowledge-base/4800

The command to 'save' the new settings is 'VDSL Savecfg'; otherwise, a reboot will reverse settings back to how they were.
Title: Re: new vigor 2866ax snr change
Post by: g3uiss on May 15, 2022, 02:43:38 AM
Nothing to do with the DSLAM
Title: Re: new vigor 2866ax snr change
Post by: ste91 on May 15, 2022, 12:13:34 PM
Unless something has changed with the newer models and does need a save command now, on my 2820 I never needed to use vdsl_savecfg' after changing the setting. Would just say 'snr update successful restarting modem....' (same as in that link) then resync at the desired snr without needing to reboot the device.
Title: Re: new vigor 2866ax snr change
Post by: Edinburgh_lad on May 17, 2022, 12:10:00 PM
It'll work without 'savecfg' and the settings will be updated.

However, this command saves the configuration to the flash memory, so if you don't 'savecfg', your settings will be reverted/lost after the next reboot.

@g3uiss I've read somewhere that some don't allow SNR changes, so good to know this is incorrect.
Title: Re: new vigor 2866ax snr change
Post by: ste91 on May 17, 2022, 02:45:21 PM
@ Edinburgh_lad that is not true, on previous models it works without having to issue the savecfg command after, and setting is updated even after reboot. Sorry to sound like an arse but have you even done this on draytek's before?!
Title: Re: new vigor 2866ax snr change
Post by: lofgents on May 17, 2022, 05:49:13 PM
I have a 2765 and can confirm once the command for vdsl snr is set the device restarts and there is no need to do anything else, the setting therefore survives any reboot or loss of power. It would be interesting to know which models of Draytek work with the vdsl snr adjustment. Previously I had a 165 and that also worked. I roughly go from 32 meg download to as high as 41 without any compromises on line stability.
Title: Re: new vigor 2866ax snr change
Post by: Edinburgh_lad on May 17, 2022, 10:30:24 PM
@ Edinburgh_lad that is not true, on previous models it works without having to issue the savecfg command after, and setting is updated even after reboot. Sorry to sound like an arse but have you even done this on draytek's before?!

There's no need to be arrogant about it.

No-one is asking you to use 'savecfg', so don't feel compelled to use it, you know, if you don't want to or know better.

The savecfg command (if it's there, it's there for a reason) is to ensure that the configuration is saved to the flash memory and that the SNR stays as requested etc.

My line, for example, suffers from some interference, which occurs locally (our pole only). Without the savecfg command, the DSLAM would eventually reduce (and has reduced) my SNR to 3db after a period of relative stability, causing my line then to become less stable. The savecfg command ensures that the SNR stays at 6db until I call for a new SNR change (or do a complete reset of the router).

PS Not Draytek's but Drayteks. The apostrophe is only used for possession and contraction, but rarely for the plural (exception is, for example, CD's, though it's CDs more often these days).