Download speed suddenly decreased & latency increased overnight

[#1]

Hi everyone.

On the 17th July overnight my Fibre Unlimited Broadband has been affected as below:

Download Speed - decrease from a consistent 73Mb to 59Mb

Latency - increase from a consistent 18ms to 33ms+ - this is what my mother gets on her 8Mb Sky copper ADSL!

The above is really obvious when online gaming (which I mostly use this connection for), and now even when accessing web pages, loading up smart TV services, the ping response/latency makes a noticeable change in the UI performance of these apps.

Why would this just change overnight? I've had 72Mb / 18ms since May 2017 no issues at all.

Have restarted router (BIPAC BILLION 7800nxl) and the BT Wholesale Fibre modem but the same when reconnected.

Have checked the BT Wholesale speed checker site, wired ethernet to my router, nothing else running on the link, and IP Profile is now shown as 62Mb, whereas previously it was 74Mb. Latency as per above.

Tracert on www.bbc.co.uk now shows as attached screenshot.  Seems that even the first hop latency is high to shef.dial.plus.net hop.

Can anyone help or provide some advice on this please? Anything would be most welcome! 😞

[#2]

Hi there.

From what I can see your router is in sync at 73.5mbps, but there have been drops in your connection over the past 30 days.

This has likely triggered interleaving which is a form of error correction and can affect latency.

Can you try the steps Here letting us know how you get on? It may also be worth trying a different router if you can.

[#3]

Hi Gandalf,

Thanks for your reply, much appreciated.

I have carried out the "Reset your fibre modem & router" section on the link you provided - that's the only bit that's relevant to my install which is an Openreach fibre modem connected directly to the BT Master Socket then my router connected to the Openreach modem.  The issues are still in place after doing this.

What other options do you have for forcing a DLM retrain or another process that will remove interleaving from my connection and therefore enable the d'load speed & latency to return to their original value (that I've happily had consistently since being a Plusnet customer :-))

Many thanks,

[#4]

Hello @captaincave29,

Thanks for getting in touch, we would need you to connect your modem to the test socket outlined in the link my colleague Anoush has provided to see if the connection stabilises.

This will rule out internal wiring as the cause of the drops you can see in the connection above, which may be causing the error correction. Once in the test socket we would advise to get back to us here after 48 hours and we will check your connection again to see if it has improved.

(edit) In addition to this, please can you advise if you see the DSL light flash on the modem or the internet light go off or red on the router?

Please let us know if you need a micro filter as we can arrange one for you.

[#5]

Hi Sammy,

I have the openreach master socket with built in filter, with the openreach fibre modem connected directly to it via rj11 cable. Do you want me to connect a microfilter to the master socket test outlet then from there into the openreach modem?

Dsl lights on the openreach modem are green and stay as such, as are my router internet lights (Billion Bipac 7800nxl).

Let me know, cheers.

[#6]

Hi Sammy,
I've done that. Microfilter in test socket now & openreach modem connected, will report back in 48hrs as requested. Thanks

[#7]

Hi @captaincave29,

Thanks very much for carrying out the troubleshooting checks. Please let us know how the connection is looking after the 48 hours.

[#8]

Hi there. Connection latency is still at 30+ ms, download at 67mb. Previous was 18ms & 74mb. What can I/you do next? Thanks

[#9]

Hi @captaincave29

As far as we can see - your router is currently syncing at 73Mbps?

est OutcomePass

Test Outcome CodeGTC_FTTC_SERVICE_1102

DescriptionModem at End User is powered down. Check that modem is plugged in and switched on

Main Fault LocationOK

Sync StatusOut Of Sync

Downstream Speed73.0 Mbps

Upstream Speed20.0 Mbps

Appointment RequiredN

Fault Report AdvisedN

NTE Power StatusPowerOff

Voice Line Test ResultPass

Bridge TapNot Detected

Repetitive Electrical Impulse NoiseNot Detected

Estimated Line Length In Metres444.1

Upstream Rate AssessmentVery Good

Downstream Rate AssessmentGood

Interference PatternNot Detected

Service ImpactNo Impact Observed

Home Wiring ProblemNot Detected

Downstream Policing Discard Rate0.0

Customer Traffic LevelUpstream and Downstream Traffic Detected

TechnologyVDSL

Profile Name0.128M-80M Downstream, Interleaving Low - 0.128M-20M Upstream, Interleaving On

Can you please run a fresh Wired Speed Test and let us know your results? 

Thanks