Kitz ADSL Broadband Information
adsl spacer  
Support this site
Home Broadband ISPs Tech Routers Wiki Forum
 
     
   Compare ISP   Rate your ISP
   Glossary   Glossary
 
Please login or register.

Login with username, password and session length
Advanced search  

News:

Author Topic: Random line problem  (Read 796 times)

ARandomDave

  • Just arrived
  • *
  • Posts: 4
Random line problem
« on: July 11, 2019, 08:13:59 AM »

I have an 80/20 VDSL service from Plusnet. I use the HG612 (have also tried ECI B-Focus), and a Linux box doing ppp/iptables.

Seemingly randomly, my attainable rate drops. It will remain this way (for weeks/months if left) until the modem is rebooted or a disconnection occurs.

I've had several OR visits over the past year or more, with no fix. The most recent visit was from a multi-skilled engineer, checking for REIN with his radio but nothing found. No noisy PSU's, home plugs, christmas lights etc. The engineer's conclusion was that it was CPE related, insisting that OR don't support the old modems (I argued this for a while, but ultimately gave up)

A picture paints a thousand words, so please see the below outputs that I've been sampling from xdslcmd every 10 mins. ES increase massively at 20:50 on the 9th July (SNR and attainable rate also drop). I rebooted the CPE at ~1840 on the 10th.





Interactive versions available here:
https://snapshot.raintank.io/dashboard/snapshot/0RqRoddGA5vryNSvPD3WLHPit152LJkw
https://snapshot.raintank.io/dashboard/snapshot/2XgKvblQ5cXj62X0ehSqTA3i3XlJv0oq

The line can remain at its "normal" attainable rate for a month or two before whatever causes this occurs.

Has anyone seen something like this before, and how did you approach resolving the issue?
« Last Edit: July 11, 2019, 08:39:46 AM by ARandomDave »
Logged

ejs

  • Kitizen
  • ****
  • Posts: 1995
Re: Random line problem
« Reply #1 on: July 11, 2019, 05:36:33 PM »

It will remain this way (for weeks/months if left) until the modem is rebooted or a disconnection occurs.

So what's the actual problem? Does it matter if you just leave it that way for weeks/months? Presumably it doesn't significantly affect your usage of the Internet if you can leave it like that for weeks.
Logged

ARandomDave

  • Just arrived
  • *
  • Posts: 4
Re: Random line problem
« Reply #2 on: July 12, 2019, 07:47:03 AM »

The problem is that for some unknown reason, my DS speed drops significantly affecting our use of the service. The drop takes the line to below the minimum range estimated by OR. The issue was left for a month as a test to see if eventually return to "normal". The impact is felt with services such as Xbox Live. The line will sometimes drop to ~23Mbps, resulting in painful game/system updates that would otherwise have completed in half the time.

Practically, continuing to log the issue with my ISP and have OR come out doesn't help. Their first action before attending site is to perform a line test, which drops the line. The subsequent re-connections eventually return it to the "normal" speed.

There's also the technical person inside me who wants to know what causes the sudden drop in the first place.

What's the next step to identifying the cause?
Logged

j0hn

  • Kitizen
  • ****
  • Posts: 2618
Re: Random line problem
« Reply #3 on: July 12, 2019, 09:28:06 AM »

What's the next step to identifying the cause?

If a resync always fixes it I'd be inclined to guess it's hardware at 1 end of the link and not the line itself.

Try another modem on your end.
If that doesn't work you need to request a port swap on the DSLAM.
Logged
Plusnet FTTC 80/20 -  ECI now Huawei cab
retx low @ 3dB target SNRM
Zyxel VMG1312-B10A bridged with 1508 MTU + Asus RT-AC68U running Asuswrt-Merlin

ARandomDave

  • Just arrived
  • *
  • Posts: 4
Re: Random line problem
« Reply #4 on: July 12, 2019, 11:06:00 AM »

Thanks j0hn. Unfortunately, an OR engineer has already tried chaning the port on the DSLAM. The last visit (of 4) had the engineer re-make off several joints and move to a different pair from one joint back to the cab.

Logged

j0hn

  • Kitizen
  • ****
  • Posts: 2618
Re: Random line problem
« Reply #5 on: July 12, 2019, 11:17:55 AM »

I'm not sure what line defect would cause the issues you describe, that suddenly fixes itself upon resync.

Do you know what type of DSLAM you are connected to?

Could be a whole line card issue if a port swap didn't help.

Do you have another modem you could try other than the 2 (old) OpenReach modems?

I'd still be inclined to guess hardware at 1 end of the link, rather than the link itself.
Logged
Plusnet FTTC 80/20 -  ECI now Huawei cab
retx low @ 3dB target SNRM
Zyxel VMG1312-B10A bridged with 1508 MTU + Asus RT-AC68U running Asuswrt-Merlin

Weaver

  • Addicted Kitizen
  • *****
  • Posts: 7801
  • Retd sw dev; A&A; 4 7km ADSL2; IPv6; Firebrick
Re: Random line problem
« Reply #6 on: July 12, 2019, 06:29:48 PM »

What J0hn said. And

    W E L C O M E   T O   T H E   F O R U M   !

 ;D
Logged

ARandomDave

  • Just arrived
  • *
  • Posts: 4
Re: Random line problem
« Reply #7 on: July 12, 2019, 10:26:21 PM »

Thanks guys.

It's an ECI DSLAM

I've replaced the HG612 with a Cisco C887VA configured to act as a bridge to keep the rest of the setup the same. I've cobbled together a similar data collection mechanism. I'll wait for everything to stabilise and see what happens next.
« Last Edit: July 13, 2019, 07:14:24 AM by ARandomDave »
Logged
 

anything