Issues With 38mb Fibre

[#1]

Hi all
I raised a call yesterday with Plusnet support who are in the process of testing my line etc before logging a call for an engineer. I just thought it may be useful to ask on here too, to see if anyone has any thoughts or advice, so thanks in advance!
For the last few days my connection has been intermittent,  culminating in my having no connection at all on Friday night. At the moment I am connected but seem to be limited to 16mb, and every so often I am disconnected again. The issue is definitely with the connection not the router as it's the DSL light on the Openreach modem that just flashes and won't connect or goes off completely. I'm puzzled now as to how it is connected but will not go above 16mb. Prior to the issues my wifi ran at 35-37mb constantly and was very stable. I have powered off and reset the modem and router a number of times and have tried leaving powered down for 30mins or so before restarting.
Not sure what the problem could be so any thoughts appreciated! Thanks.

[#2]

It sounds as if there has been some fault, possibly temporary or possibly more permanent (until fixed).  As a result, DLM has seen instability on the line and lowered the speed allowed between the cabinet and your modem.  It is possible that the interrupted single from powering off the modem several times was also seen as noise by DLM and added to its conviction something is wrong.  At least powering off is better than disconnecting the phone cable to the modem.
If you run the BT wholewsale tester at http://speedtest.btwholesale.com/ and when complete run the Further Diagnostics and post its results that should give more idea of whether DLM has intervened.

[#3]

Hi, thanks for your reply. Results attached. It returned an error on the further diagnostics test though.

[#4]

I am afraid that means we can't see the useful information (unless you have a modem that can get the stats; either your own or an unlocked Openreach one); you will have to wait for Plusnet service to do their thing.  Good luck with getting it sorted; meanwhile try to resist the temptation to play with the modem too much in case it makes things worse.

[#5]

Yeah, I didn't know anything about DLM, so having just read up on it it seems likely that this is what's happened. I had no idea that restarting the modem could trigger anything like that. It seems reasonably stable at 16MB now and just got near perfect results on Ookla's pingtest too, so fingers crossed either the DLM will sort the line out itself or Plusnet will sort it. Thanks again for your help.

[#6]

If DLM has taken control, You'll have to wait for line to become stable if no fault is found. I've been chucked on interleaving but line is stable 

[#7]

I accidentally unplugged my modem and it went from 30Mbps to 26.6Mbps it's taken a month to get back but it happened on Saturday 

honestly no practical difference

[#8]

Good luck with DLM giving you your proper speed back ~ sadly it can often take 2 to 3 weeks.
and just got near perfect results on Ookla's pingtest too  You were lucky if they are really good;  DLM usually adds interleaving as well as slowing the line down when it feels that it needs to intervene; and that adds around 8ms (typically) to ping times.cmd.  You can generally tell by running 'tracert bbc.co.uk' at the command line.
The first line should give figures of 1ms or below.  Then look for the lowest consistent values in the lines below (*),  If these are around 10ms or less you probably are not interleaved.  If they are around 15ms or more you probably are.  (Depends on your location and how it is tied into the Plusnet network.,)
(*) generally I say look in the second line.  However, some servers give low priority to tracert requests and so give values that are higher than they should; which means you often see lower values for servers further down the route than for those nearer.  Another test for this is to see what the server in step 2 is, and to ping that ... see below.
~~~~~

C:\utils>tracert bbc.co.uk
Tracing route to bbc.co.uk [212.58.246.103]
over a maximum of 30 hops:
  1    <1 ms    <1 ms    <1 ms  BTHomeHub.home [192.168.1.254]
  2    34 ms    14 ms    15 ms  lo0-central10.pcl-ag02.plus.net [195.166.128.183]  <<< stupidly large values, so use the address 195.166.128.183 in the ping below
  3    18 ms     9 ms     9 ms  link-a-central10.pcl-gw01.plus.net [212.159.2.164]
  4     9 ms     9 ms     9 ms  xe-10-1-0.pcl-cr01.plus.net [212.159.0.196]                  <<< this being a (fairly) low value shown I am not on interleaving
  5     9 ms     9 ms     9 ms  ae1.ptw-cr01.plus.net [195.166.129.0]
  6     9 ms     9 ms     9 ms  kingston-gw.thdo.bbc.co.uk [212.58.239.6]
  7     *        *        *     Request timed out.
  8    11 ms    10 ms    10 ms  ae0.er02.cwwtf.bbc.co.uk [132.185.254.90]
  9    11 ms    11 ms    11 ms  132.185.255.165
 10    10 ms    10 ms    10 ms  fmt-vip132.cwwtf.bbc.co.uk [212.58.246.103]
Trace complete.
C:\utils>ping 195.166.128.183
Pinging 195.166.128.183 with 32 bytes of data:
Reply from 195.166.128.183: bytes=32 time=13ms TTL=126
Reply from 195.166.128.183: bytes=32 time=10ms TTL=126
Reply from 195.166.128.183: bytes=32 time=10ms TTL=126
Reply from 195.166.128.183: bytes=32 time=10ms TTL=126

[#9]

Your line was very very intermittent, disconnecting every few minutes as you can see on the graph below.
As the other posters in this thread have mentioned, there's very little we can do remotely on a fibre connection to remove banding or improve speeds. Generally a line reset is only performed after an engineers visit has occurred, and only if they've repaired something.
Without an engineer it can take a couple of weeks for the DLM to see the line as stable and start to improve the speeds again.
I see you've raised a fault ticket so we'll get that picked up and tested, we'll be in touch once that's happened.

[#10]

Thanks for that, the graph is very useful! So it does seem that it's finally stabilised....
I like the idea of DLM in theory but it should be able to adjust / react more quickly, or at least be manually adjusted / reset more easily. In practice it just means that right now I'm getting less than half the download speed I'm paying for for no real reason, I don't much like the prospect of remaining on 16mb for weeks when I am paying the same monthly fee and I know my line is fine to run at 38mb... But I imagine there's not very much I can do about it?
Thanks again for your help.

[#11]

I'd suggest leaving the fault ticket open for now, our faults team may spot something that I haven't and therefore might request an engineer.