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Normally a solid 76mb down to @55mb with latency issues today

teal
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Registered: 01-03-2018

Normally a solid 76mb down to @55mb with latency issues today

Hi,

Ive enjoyed a rock solid connection of 76mb with 15mb upstream, low latency and no packet loss problems until today.

 

Unfortunately, I now have 50mb-60mb with latency issues.

 

Any known regional issues?  Any suggestions?

 

Thanks

 

teal

16 REPLIES
teal
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Re: Normally a solid 76mb down to @55mb with latency issues today

Also, I notice that hops 2 and 3 of all tracerts time out - is this normal on plusnet infrastructure?

Community Veteran
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Registered: 13-08-2015

Re: Normally a solid 76mb down to @55mb with latency issues today

Many devices will not respond to pings/tracerts.

Speed tests can also vary, start with the basics, what are your connection speeds - a copy of the Helpdesk Page would be a good place to start - make sure you remove the personal info. 

BrainSuperGlue
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Re: Normally a solid 76mb down to @55mb with latency issues today

Storms and other weather can add noise on the line. Your signal to noise ratio could be very low. Which router are you using? It may have some stats. Have the same issue you do. My SNR is down to 4.2dbm on downstream. My SNR for upstream is 15dbm, v healthy.

teal
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Re: Normally a solid 76mb down to @55mb with latency issues today

Hey,

Thanks for your replies.  Below is the helpdesk page info:

What do you think of the SNR? I dont know the ideal parameters...

1. Product name: Plusnet Hub
2. Serial number:  
3. Firmware version: Software version 4.7.5.1.83.8.237.2.2 Last updated 13/11/17
4. Board version: Plusnet Hub One
5. DSL uptime: 0 days, 02:38:19
6. Data rate: 19999 / 78428
7. Maximum data rate: 24914 / 76053
8. Noise margin: 15.4 / 5.4
9. Line attenuation: 21.7 / 16.0
10. Signal attenuation: 21.6 / 16.2
11. Data sent/received:  
12. Broadband username:  
13. 2.4 GHz Wireless network/SSID:  
14. 2.4 GHz Wireless connections: Disabled
15. 2.4 GHz Wireless security: WPA2
16. 2.4 GHz Wireless channel: Automatic (Smart Wireless)
17. 5 GHz Wireless network/SSID:  
18. 5 GHz Wireless connections: Enabled (802.11 a/n/ac (up to 1300 Mb/s))
19. 5 GHz Wireless security: WPA2
20. 5 GHz Wireless channel: Automatic (Smart Wireless)
21. Firewall: Default
22. MAC Address:  
23. Modulation: G.993.2 Annex B
24. Software variant: AA
25. Boot loader: 1.0.0

 

Todays Ookla test results:
 PING
22ms
 DOWNLOAD
52.64Mbps
 
 UPLOAD
15.56Mbps
 
 
Normal Ookla results: 
18
75.31
18.88

 

1 1 ms 1 ms 1 ms dsldevice.lan [192.168.1.254]
2 * * * Request timed out.
3 15 ms 15 ms 16 ms 133.hiper04.sheff.dial.plus.net.uk [195.166.143.133]
4 16 ms 24 ms 16 ms be3-3102.pcn-ir02.plus.net [195.166.143.132]
5 16 ms 16 ms 15 ms 195.99.125.144
6 15 ms 15 ms 16 ms peer7-et-0-1-4.telehouse.ukcore.bt.net [109.159.252.94]
7 16 ms 15 ms 15 ms peer5-te0-9-0-32.telehouse.ukcore.bt.net [195.99.126.81]
8 16 ms 16 ms 15 ms 151.101.64.81

-This time tracert only has hop 3 timed out.

 

Awaiting comments/advice Smiley

BrainSuperGlue
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Re: Normally a solid 76mb down to @55mb with latency issues today

That looks very similar to mine.

The stats give upload/download. You've got enough signal to be able to sync to the exchange connection (DSLAM) which has given you 20Mbps up and 78.5Mbps down.

However, the sync rate isn't the usage rate which you're seeing as 15.56Mbps up and 52.64Mbps down.

[I've updated this for clarity]

Signal to Noise ratio is the key here. Make a note of the following paragraph.

"< 6dB: An SNR of less than 6 dB usually will result in line issues.

7dB - 10dB: This is a decent SNR but doesn't leave much room for variances in line conditions.
11dB - 20dB: Most people who live within a short amount of distance from the street cabinet (less than 1500 feet) will have an SNR within that range.  This will result in little to no sync problems.
20dB - 28dB: Outstanding SNR, you must have the street cabinet as your next door neighbour."

The gap between the signal and the noise on the line is the key. When the line syncs, the network equipment listens the line noise to set the speed. At the time of the sync the SNR is OK so the SNR margin is set low.

The margin shown represents the margin to keep the line under sync. Whilst a higher SNR is good, a lower SNRM is better IF the line is stable and didn't get bursty noise.

I'll explain more in another post after I get a cup of tea.
 






 
BrainSuperGlue
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Re: Normally a solid 76mb down to @55mb with latency issues today

to continue. 

Here are my VDSL line stats. Similar to yours but you have more signal lost attenuation over the line, you could be further away from the street cabinet than I am.

LineStatsPN.PNG

My Asus router also gives additional info.

There are two modes listed, Interleaved and Fastpath. If you have low noise line then it will give you connection without so much checking for noise, Fastpath. My upstream is good hence Fastpath.

My downstream is on a line that is susceptible to noise, so the signal is put into smaller sections or Interleaved. It means that if there is sudden noise on the line then a smaller amount of signal is lost and has to be resent. The problem with this is that you take a speed hit.

Look at Power. In order to get my downstream signal nice and loud against the noise, more power is needed as compared to the quieter upsteam where much less power is needed.

I used to get a nice 72Mbps until we had a storm here and it now bumps between 56 and 66Mbps. The storm didn't come inside the house so I don't believe it's my equipment. I think an external cable has gotten loose somewhere and need replacing.

That's why I've asked for an engineer.

RealAleMadrid
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Re: Normally a solid 76mb down to @55mb with latency issues today

@BrainSuperGlue  I don't think your info about signal to noise ratio is correct, actually it is complete nonsense. Firstly modem stats show SNRM values - signal to noise ratio margin which is designed to allow for line variations without losing sync. The normal default value is 6dB and the vast majority of lines work perfectly well with this value. In fact the BT Openreach DLM system (Dynamic Line Management) which controls FTTC line parameters can reduce SNRM to as low as 3dB if a line is stable and showing low error count. This decrease in SNRM can significantly improve the sync speed  and therefore the throughput speed for these lines. Of course on shorter lines the modem is syncing at the maximum 80/20Mbps so the SNRM margin will be higher than the default value.

The fact that the OP's throughput speeds are lower than expected is nothing to do with the SNRM value as you claim. There will be other reasons for the drop in speed.

I think you will be very lucky to get an engineer to look at your problem, you are probably well within the expected speed range for your line.

 

 

BrainSuperGlue
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Re: Normally a solid 76mb down to @55mb with latency issues today

Hi RealAleMadrid,

You're missing my point.

Yes, I agree that the move by Openreach is to bring down the line SNRM to 3dB as they have been testing and migrating over the last year or so. What I'm saying is that for me and apparently for the OP, it appears we have bursty noise on our lines. That when the line gets synced it is reasonably quiet and the line gets given a low SNRM. If the line stayed quiet then countermeasures wouldn't be needed but instead of raising the SNRM and lowering the speed it is upping the sending power, interleaving and lowering the speed. Our lines lines aren't losing sync at the SNRM we have as designed but our lines could be less prone to spiky noise as mine was prior to the storm. 

BSG

Plusnet Help Team
Plusnet Help Team
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Registered: 21-04-2017

Re: Normally a solid 76mb down to @55mb with latency issues today

Hi teal. Sorry to hear you're having connection problems. Our tests aren't finding the cause of that.

Are your devices connecting over WiFi or straight to the router using an ethernet cable?

If this post resolved your issue please click the 'This fixed my problem' button
 Anoush Mortazavi
 Plusnet Help Team
teal
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Re: Normally a solid 76mb down to @55mb with latency issues today

Hi Gandalf,

Thanks for the reply. 

To answer your question, I use a LAN cable for my PC.

 

The initial problem was on the 1stMarch but in the next day or two, it resolved and returned to normal performance.  I was waiting for the 'help and support page question (169536444) to be updated before closing the query and updating this thread.

 

But today the problem has returned as is reflected on the speedtests (see attached jpg).  

 

Is it possible that the engineers testing was done on one of the good days? 2ndMarch - 5th march?

The truth is Im not bothered so much about the reduced bandwidth so much as the problem with gaming.  In games, my characters are running slow, then fast, repeatedly and consistently - Ive never experienced this before, but it seems to corelate with the reduced bandwidth on a speed test.

 

 

-teal

 

teal
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Re: Normally a solid 76mb down to @55mb with latency issues today

And since yesterday, it has returned to normal excellent performance.  No gaming lag, no reduced bandwidth.  As the problem happens for  full single days at a time, is it possible its the management or throttling system doing this somehow?

 

7118708208

Plusnet Help Team
Plusnet Help Team
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Re: Normally a solid 76mb down to @55mb with latency issues today

Hi teal.

Is it possible that the engineers testing was done on one of the good days? 2ndMarch - 5th march?

Doesn't look like your fault ticket has been picked up yet.

 

Our tests aren't finding any issues at all...

Test Outcome Pass
Test Outcome Code GTC_FTTC_SERVICE_0000
Description GEA service test completed and no fault found .
Main Fault Location OK
Sync Status In Sync
Downstream Speed 79.3 Mbps
Upstream Speed 20.0 Mbps
Appointment Required N
Fault Report Advised N
NTE Power Status PowerOn
Voice Line Test Result Pass
Bridge Tap Not Detected
Radio Frequency Ingress Not Detected
Repetitive Electrical Impulse Noise Not Detected
Cross Talk Not Detected
Estimated Line Length In Metres 496.7
Upstream Rate Assessment Very Good
Downstream Rate Assessment Very Good
Interference Pattern Not Detected
Service Impact No Impact Observed
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, Retransmission Low - 0.128M-20M Upstream, Error Protection Off
Time Stamp 2018-02-22T15:15:00
Parameters MIN MAX AVG
Down Stream Line Rate 78.5 Mbps 79.9 Mbps 79.7 Mbps
Up Stream Line Rate 19.9 Mbps 20.0 Mbps 19.9 Mbps
Up Time 805.0 Sec 900.0 Sec 899.7 Sec
Retrains 0.0 1.0 0.0
Current and Last 15 Minute Bin Performance
Parameters Last Traffic Count(Upto 15 mins) Current Traffic Count(Upto 15 mins)
Start Time Stamp 2018-03-07T14:32:30Z 2018-03-07T14:47:30Z
Ingress Code Violation 0 0
Egress Code Violation 0 0
Errored Seconds 0 0
Severely Errored Seconds 0 0
Unavailable Seconds 0 0

 

As the problem happens for  full single days at a time, is it possible its the management or throttling system doing this somehow?

It's unlikely as the dynamic line management shouldn't work in that way.

From the Profile Name above, there's no banding applied either.

 

Are you able to replicate the problems using a different computer?

If this post resolved your issue please click the 'This fixed my problem' button
 Anoush Mortazavi
 Plusnet Help Team
teal
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Re: Normally a solid 76mb down to @55mb with latency issues today

 

Are you able to replicate the problems using a different computer?

No, though I can use a speed test on my mobile easily enough next time it happens to verify the reduced performance on the pc bandwidth.  

 

The only two days the problem happened were: 1st march and 6th march  - so the above tests may not have caught the issues?

 

I appreciate your help though Gandalf.  Ill be sure to post again as soon as and if it reoccurs.  And Ill use my mobile to wifi speed check alongside the pc; and Ill post some video of the weird effects it has on gaming.

 

Thanks in the meantime Cheesy

Plusnet Help Team
Plusnet Help Team
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Re: Normally a solid 76mb down to @55mb with latency issues today

No problems at all. Keep us posted! Smiley

If this post resolved your issue please click the 'This fixed my problem' button
 Anoush Mortazavi
 Plusnet Help Team