Unlimited FTTC. Periodic drop of Download Speed. Graphed Pattern of drops

[#1]

Hi.

I have been on FTTC using the Plusnet Hub 2, for the past 8 months initially with no issues.

At the beginning of Sept 23 I lost my landline phone connection, however the Broadband connection continued at 24Mbps to 30Mbps. OpenReach attended on 4th Sep and, after several hours with no connection (broadband or phone) service was restored. I suspect that I was switched to another circuit.

Since that time I have observed my DL speed dropping periodically to 3Mbps to 5Mbps for several hours each day.

To gather evidence, I scripted the speedtest CLI utility to run every 30 minutes on a Raspberry Pi with a wired ethernet connection direct to the Hub. The results go to a csv file which I processed in Libre office to give the graph below:

Ping in ms Speeds Mpbs X mmdd:hhmm

The graph is showing drops once per day, starting mainly mid to late afternoon. Recovery starts at 23:15 and takes 1 to 1.5 hours. The drop in DL speed correlates with an increase in Ping time

The speed drops do not coincide with heavy internet usage.

Hub stats at this point show Hub up time 5 days 19 hours. Network Uptime 14 hrs

Data usage over the 5 days 19 hours (May include some intra LAN traffic)

32GB NOW box only active 08:00 to 11:00 NOT coincident with any speed drop

9.4GB Raspberry pi- Correlates to 260 speed tests at 41 MB/test

8.8GB Streaming

9.3GB Phones

3.1GB Laptops

It almost looks as if I am having to share my line with a heavy user?

Any suggestions please?

TIA DAVE1

[#2 · Accepted solution]

@davev1   Your graph shows clear evidence of reduced throughput at peak times which is caused by congestion in the backhaul at the exchange known as a hot VLAN. The problem is BT wholesale will never admit it without a lot of pressure from Plusnet. Unfortunately Plusnet seem to have very little influence to get the problem acknowledged, let alone fixed.

So expect Plusnet to arrange multiple engineer visits although they can do nothing to fix it. After several of these, probably with a replacement router thrown in. Plusnet should be able to raise an escalation with BT wholesale who will probably reject it and deny any problem with the exchange VLANs. Apparently their monitoring is not too good. Eventually they may admit that there is congestion and move your connection to a different VLAN. 

Have a look at this thread from 6 years ago, just a quick warning, it's painfully long and a complete nightmare for the customer. 😫   For a comparison with your speed graphs see message #27

https://community.plus.net/t5/Fibre-Broadband/When-congestion-is-given-as-a-reason-for-speed-drops-h... 

Perhaps you could refer support to this linked thread and hope they realise what they need to do. Best of luck.😁

[#3]

Hi @RealAleMadrid. Thank you very much for the advice. It does at least give me a starting point when I attempt to get Plusnet to act on it.

I will start on the long trek!!!

Kind regards

Dave1