cancel
Showing results for 
Search instead for 
Did you mean: 

Help of diagnosing my high error rates causing resyncs

Community Veteran
Posts: 38,460
Thanks: 1,031
Fixes: 62
Registered: ‎15-06-2007

Help of diagnosing my high error rates causing resyncs

Typically I am getting between 3000 and 6000 FEC per minute

The last time a GEA test was run this was the result

Test Outcome Pass
Test Outcome Code GTC_FTTC_SERVICE_0003
Description No problem found, OAM test is not currently supported on this line.
Main Fault Location OK
Sync Status In Sync
Downstream Speed 51.8 Mbps
Upstream Speed 10.1 Mbps
Appointment Required N
Fault Report Advised N
NTE Power Status PowerOn
Voice Line Test Result Pass
Bridge Tap Not Detected
Repetitive Electrical Impulse Noise Not Detected
Estimated Line Length In Metres 730.7
Upstream Rate Assessment Reasonable
Downstream Rate Assessment Good
Interference Pattern Regular Interference Observed Daily
Service Impact No Impact Observed
Interference Duration Longest Occurrence ; 00:00 to 23:45
Interference Location Customer Premise
Interference Observed In Days 14
Home Wiring Problem Not Detected
Downstream Policing Discard Rate 0.0
Customer Traffic Level Upstream and Downstream Traffic Detected
Technology VDSL
Profile Name 0.128M-80M Downstream 3dB, Retransmission High - 0.128M-20M Upstream, Error Protection Off
Time Stamp 2017-05-28T10:15:00

The relevant bit is this

Interference Location

Customer Premise

Profile Name

0.128M-80M Downstream 3dB, Retransmission High - 0.128M-20M Upstream, Error Protection Off

Interference Pattern

Regular Interference Observed Daily

Having disconnected everything near the router and it didn't change where do I go next and would a new GEA Test provide any further information

My setup is

Incoming feed to BT Master socket with BT filtered faceplate and no internal wiring and a Billion 8800NL router connected by a screened cable

Would it be worth trying a new router (Hub 1 perhaps) to rule out the router or router power supply

Would a new GEA Test provide any further information

 It just got worse so I expect a resync coming up

2018-02-10_232531.jpg

41 REPLIES
Community Veteran
Posts: 5,187
Thanks: 486
Fixes: 21
Registered: ‎10-06-2010

Re: Help of diagnosing my high error rates causing resyncs

Have you tried using the ordinary DSL cable that came with the modem/router? Sometimes the fancy cables don't help or even make things worse.

Community Veteran
Posts: 38,460
Thanks: 1,031
Fixes: 62
Registered: ‎15-06-2007

Re: Help of diagnosing my high error rates causing resyncs

nope

will dig out a normal cable from my bits box and try that - probably tomorrow

Community Veteran
Posts: 1,595
Thanks: 278
Fixes: 33
Registered: ‎13-08-2015

Re: Help of diagnosing my high error rates causing resyncs

Also, the graph is over a short period, do you have one over 24 hours? And do you get the interference only between 11 and 12 at night?

Community Veteran
Posts: 38,460
Thanks: 1,031
Fixes: 62
Registered: ‎15-06-2007

Re: Help of diagnosing my high error rates causing resyncs

this is more typical

2018-02-11_150004.jpg

and is the steady background errors even when there is virtually no internet usage

Community Veteran
Posts: 2,497
Thanks: 294
Fixes: 2
Registered: ‎04-08-2009

Re: Help of diagnosing my high error rates causing resyncs

@Oldjim

Now there's a thing! Please see attached snapshot. The FEC rate on my setup was around 7000/min until I picked up the phone at about 15.37, then it shot up to nearly 30000/min. So I disconnected the phone completely and the FEC rate dropped to a max of 100/min. Then I replaced the line filter and it's dropped to next to nothing. So the line filter must be up the spout. Try replacing yours and see the effect. It's stayed very low since then.

 

FEC-2018-02-11-15.47.16.png

 

Community Veteran
Posts: 38,460
Thanks: 1,031
Fixes: 62
Registered: ‎15-06-2007

Re: Help of diagnosing my high error rates causing resyncs

Worth a try - I have a few rats tail filters knocking about as well as an old filtered faceplate

Community Veteran
Posts: 2,497
Thanks: 294
Fixes: 2
Registered: ‎04-08-2009

Re: Help of diagnosing my high error rates causing resyncs

It's also dropped the bitswap rate to zero and the SNRM has improved.

wisty
Pro
Posts: 470
Thanks: 63
Fixes: 6
Registered: ‎30-07-2007

Re: Help of diagnosing my high error rates causing resyncs

I don't think FEC errors are causing the resync. 

AIUI FEC errors are the kind off errors (single bit in a packet?)  which the error correction algorithms in the modem simply fix on the fly. I don't think the DSLAM ever sees those as errors.

More important are the CRC errors which (I think) cause a retransmission of the packet and the errored seconds count which shows how often it happens. 

My FTTC line which is clean and rock solid shows a similar set of numbers - it rises when I am streaming TV or watching BT TV on the multicast -- as I would expect, more packets = more single bit errors.

 

Community Veteran
Posts: 5,187
Thanks: 486
Fixes: 21
Registered: ‎10-06-2010

Re: Help of diagnosing my high error rates causing resyncs

The increased FEC rate may well not be directly causing the resync, but it's probably an indication of something happening like increased noise/interference that does eventually cause a resync.

The amount of Internet traffic will have no relation to the FEC rate, the FEC process operates at a lower level, the rate of VDSL2 frames will be constant depending on the line rate. If your FEC rate increases while watching TV it'll be caused by something other than the level of Internet traffic.

wisty
Pro
Posts: 470
Thanks: 63
Fixes: 6
Registered: ‎30-07-2007

Re: Help of diagnosing my high error rates causing resyncs


wrote:

 

The amount of Internet traffic will have no relation to the FEC rate, the FEC process operates at a lower level, the rate of VDSL2 frames will be constant depending on the line rate. 


Thanks - you learn every day. I assumed that VDSL2 frame traffic stopped (or went down to keep alive rates) if there was no content.

It's possible that my increase is driven by interference from the powerline adapters that carry the multicast traffic. I will replace them with a cable sometime and test that fact.

Community Veteran
Posts: 38,460
Thanks: 1,031
Fixes: 62
Registered: ‎15-06-2007

Re: Help of diagnosing my high error rates causing resyncs

filter had no effect so unless Plusnet can make a suggestion I will just live with it

Community Veteran
Posts: 2,497
Thanks: 294
Fixes: 2
Registered: ‎04-08-2009

Re: Help of diagnosing my high error rates causing resyncs

Does unplugging all the phones including filters have any effect? Are you hard wired to the router or on WiFi from it?

Community Veteran
Posts: 38,460
Thanks: 1,031
Fixes: 62
Registered: ‎15-06-2007

Re: Help of diagnosing my high error rates causing resyncs

Disconnecting the phone has no effect and two devices are hard wired and two (or more) are wireless

Community Veteran
Posts: 2,497
Thanks: 294
Fixes: 2
Registered: ‎04-08-2009

Re: Help of diagnosing my high error rates causing resyncs

One possibility is that the errors aren't real! Have you got another router you can try? What is the bitswap rate like? 

And what kind of state is your wiring like coming in to the house and within it?

In view of the fact that you are getting disconnections as well I would guess that there is a high resistance joint on the line somewhere that's flapping about or getting wet or both.