DrayTek UK Users' Community Forum

Help, Advice and Solutions from DrayTek Users

Cause of unstable VDSL line on 2862n

  • eveares
  • Topic Author
  • Offline
  • Junior Member
  • Junior Member
More
09 Nov 2019 13:29 #95192 by eveares
Replied by eveares on topic Re: Cause of unstable VDSL line on 2862n
Funny enough, since upgrading the firmware to 3.9.1.2_BT , the Bitswap on the downstream is now off. Still at 3DB SNR margin on the downstream though.

Any chance of getting a custom modem code from draytek? And will that get things as good as mine?

The first picture is my grandparents currently, the second is my 2860.

(Based on Up time of 38 Minutes)


(Based on Up time of 136 Hours)


Regards: Elliott.

Please Log in or Create an account to join the conversation.

  • eveares
  • Topic Author
  • Offline
  • Junior Member
  • Junior Member
More
09 Nov 2019 13:48 #95193 by eveares
Replied by eveares on topic Re: Cause of unstable VDSL line on 2862n
Just one more thought, is it worth using my old standard Openreach ECI VDSL modem that I may still have laying around that plusnet sent me when I took out my fibre broadband service in 2013.

Will it work at my grandparents in this day and age, baring in mind it has not been in use since about 2015.

Please Log in or Create an account to join the conversation.

More
09 Nov 2019 18:52 #95194 by x64
Certainly try the other modem, at first to see what it syncs at and then get a feel for stability. Maybe you can put it in bridge mode on LAN5 of the draytek, if it syncs faster and/or is more stable. Any stats you could get out of it would be a handy comparison as well.

In the preceding post, YOUR line is on a cab with Infineon chipset (the "[IFTN]" in the ATU-C info) - That (I think) is the same manufacturer that the 2862 uses (someone confirm?), and should be more compatible with the 2862 than the BDCM cab... But short of moving, there is not a lot they can do about the cab!....

Don't get hung up on Bitswap. That will flick in and out as line conditions determine and is not a performance hit in any way (as interleave>1 would be). Bitswap redistributes 'bits' of your data between the tones that DSL technologies uses, in order to make more use of the currently more reliable tones. It's normal for there to be a lot of this going on.. Bitswap does not change the speed of sync, it makes better use of a little slack in what has been negotiated (for stability)

Please Log in or Create an account to join the conversation.

  • eveares
  • Topic Author
  • Offline
  • Junior Member
  • Junior Member
More
10 Nov 2019 17:16 #95195 by eveares
Replied by eveares on topic Re: Cause of unstable VDSL line on 2862n
Just ran "VDSL SNR 30" in the command line to increase the downstream SNR margin to +3dB.

Hopefully it will make a difference. Downstream SNR Margin is now at 7dB and Upstream SNR margin is at 6dB.

Please Log in or Create an account to join the conversation.

More
11 Nov 2019 09:44 #95196 by m112
Replied by m112 on topic Re: Cause of unstable VDSL line on 2862n
I have simialiar issue with 2862 router. I have BT with 55Download/10upload max.
I have been useing BT home hub 5 or 6 for last couple of years and its been fine (I was getting around 48-50download/9upload), recently I got hold of 2862n.
Draytek is syncing at the maxium speed 54000/10000 however the speed of the internet speed fluctates between 10Mbps-40 Mbps or drops completely.

I have the latest FW, and also tried different modems - but changing them doesnt do anything.

Please Log in or Create an account to join the conversation.

More
11 Nov 2019 18:21 #95197 by x64

eveares wrote:
Just ran "VDSL SNR 30" in the command line to increase the downstream SNR margin to +3dB.

Hopefully it will make a difference. Downstream SNR Margin is now at 7dB and Upstream SNR margin is at 6dB.


Once that settles down, it would be interesting to see your DSL stats again. The downstream SNRM is the one that has greater interest (bit also the Attainable rates)

Please Log in or Create an account to join the conversation.

Moderators: ChrisSami