Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[AStalUK]

My line used to sync at a stable 69Mpbs, but more recently it's been syncing at 64Mbps after a line changing following some testing with a Draytek Vigor 166 which caused the line to drop down to 50Mbps+ over the cause of a week.  But for the last week the line has dropped down to 54Mbps, I've tried leaving the modem off for 30mins+ but so far it won't sync any higher.

Before I flag this with BT can someone take a look at my modem stats and see if they think anything is off.

 vdsl status

  ---------------------- ATU-R Info (hw: annex A, f/w: annex A/B/C) -----------
   Running Mode            :      17A       State                : SHOWTIME
   DS Actual Rate          : 54997000 bps   US Actual Rate       : 14410000 bps
   DS Attainable Rate      : 46722488 bps   US Attainable Rate   : 14294000 bps
   DS Path Mode            :        Fast    US Path Mode         :        Fast
   DS Interleave Depth     :        1       US Interleave Depth  :        1
   NE Current Attenuation  :       18 dB    Cur SNR Margin       :        4  dB
   DS actual PSD           :     7. 7 dB    US actual PSD        :    15. 5  dB
   NE CRC Count            :        0       FE CRC Count         :     7698
   NE ES Count             :        0       FE  ES Count         :     6624
   Xdsl Reset Times        :        0       Xdsl Link  Times     :        1
   ITU Version[0]          : fe004452       ITU Version[1]       : 41590000
   VDSL Firmware Version   : 05-07-06-0D-01-07   [with Vectoring support]
   Power Management Mode   : DSL_G997_PMS_L0
   Test Mode               : DISABLE
  -------------------------------- ATU-C Info ---------------------------------
   Far Current Attenuation :       22 dB    Far SNR Margin       :        5  dB
   CO ITU Version[0]       : b5004244       CO ITU Version[1]    : 434dc190
   DSLAM CHIPSET VENDOR    : < BDCM >
> vdsl status more

  ---------------------- ATU-R Info (hw: annex A, f/w: annex A/B/C) -----------
                  Near End        Far End    Note
 Trellis      :      1               1
 Bitswap      :      1               1
 ReTxEnable   :      0               1
 VirtualNoise :      0               0
 20BitSupport :      0               0
 LatencyPath  :      0               0
 LOS          :      0               0
 LOF          :      0               0
 LPR          :      0               0
 LOM          :      0               0
 SosSuccess   :      0               0
 NCD          :      0               0
 LCD          :      0               0
 FECS         :      0            288089 (seconds)
 ES           :      0            6624 (seconds)
 SES          :      0               1 (seconds)
 LOSS         :      0               0 (seconds)
 UAS          :     32            12581 (seconds)
 HECError     :      0               0
 CRC          :      0            7698
 RsCorrection :      0               0
 INP          :      0             250 (symbols)
 InterleaveDelay :      0              15 (1/100 ms)
 NFEC         :    254              32
 RFEC         :     16              16
 LSYMB        :   3868              16
 INTLVBLOCK   :    127              32
 AELEM        :      0            ----

[gt94sss2]

Your line has been banded. Your best option is just to leave the modern connected for a few weeks and wait for DLM to change its mind.

Alternatively, you could ask your ISP for a DLM reset.

[j0hn]

Your line has been banded. Your best option is just to leave the modern connected for a few weeks and wait for DLM to change its mind.

Alternatively, you could ask your ISP for a DLM reset.

What he said ^^

It's likely the testing of the Vigor 166 caused the line to be capped/banded.
All those resyncs when testing are seen as instability and the DLM applies banding to deal with it.

It can take anything from a few weeks to a few months for the banding to go completely. It usually eases off in stages, increasing sync a few Mb at a time.

BT are unlikely to help with a DLM reset if the current sync is within your contractual estimates unfortunately.

[AStalUK]

Thanks for the replies, how do you know it's been banded, is this just experience or something within the stats that shows this?

[j0hn]

The sync is usually an exact figure, that isn't your package speed.
In your case the sync appears capped at 55Mb which shows as 54,999 on most modems (54,997 on your modem).
The sync speed is the exact same after each resync when banded.

It also usually comes with an SNRM higher than normal, with the sync speed below the lines attainable rate.
Your stats don't show this part but that could well be because you have an SNRM offset in effect on the Draytek.

Can I ask what made you buy a very expensive G.Fast modem for a VDSL2 service?
There are a number of much cheaper Draytek modems that perform much much better than the 166 on VDSL2.
In the Vigor 166 review thread on this forum the 166 was not impressive at all.
I'd only recommend the Vigor 166 for G.Fast of for anyone hoping to upgrade to it.
If you don't have G.Fast, you likely never will have it. The G.Fast rollout is over. More and more providers are also choosing to stop selling it in the few areas it is available.

[AStalUK]

I work in IT for a company and for a number of year I have used the Vigor 130's with our Meraki routers without to many problems, generally they've been rock solid and provided stable connections where the lines allow.  So seeing a newer updated Vigor modem which also supports g.fast I thought I would get one and test it out to see if it's suitable as a replacement and as you pointed out the comments in the review thread clearly show it isn't, I posted in that same thread doing some work with Draytek to try and find a solution, unfortuantely it went no where.

I reconnected the Vigor 160 to my line again recently as there was a firmware update and I wanted to see if it made any difference, the answer is a resounding no, I should have guessed that would be the case as there is no change to the firmware code.

[hushcoden]

@AStalUK I can also advise you to use a Vigor 130 (or a Zyxel VMG1312-B10A or VMG8x24-B10A) on a VDSL2 line, it seems it performs better than Vigor 166 (which I'm currently using): on my G.fast line, I'm running the Vigor166 with a beta firmware provided to me by Draytek UK support and it syncs definitely better than the default v4.2.3.1_BT firmware (different modem codes) and I no longer experience re-sync which I used to get every now and then: 47 days so far and counting 

Besides, I take it you are using the default BT firmware, and if you want to do one last test you could try the second modem code 123210_14 rather than the default 123230_05

[AStalUK]

Thanks @hushcoden, I'm just going to stick with the Vigor 130 for now, if g.fast becomes available to me maybe I'll retry the 166.