Intermittent ping spikes to 300-400ms every few minutes on FTTP (wire

[Cianito]

Hi,

Looking for help with an intermittent latency issue that started in the last month or so (previously fine). It's most noticeable when trying to play games online.

Setup: BT Smart Hub 2, Full Fibre (FTTP), 1000/1000 sync, wired Ethernet connection (issue confirmed on wired, so Wi-Fi/interference is ruled out).

Symptom: Baseline ping is normal (~30-50ms), but every few minutes it spikes to 300-400ms for around 3-4 minutes, then returns to normal, then repeats the cycle again a while later.

Troubleshooting done so far: Ran continuous ping to my hub (192.168.1.254) at the same time as ping to 8.8.8.8, during a spike. Hub ping stayed steady at ~1ms throughout so local network/hub is not the bottleneck.

Tested external ping to two independent destinations (8.8.8.8 and 1.1.1.1); both spike together at the same time, ruling out a single bad route to one destination.

Confirmed this is wired, not wireless.

Hub's Technical Log shows healthy stats (full 1000/1000 sync, Full Fibre mode on) which I believe means no local line issue.

BT's own automated fault check came back "no fault found" 

Since I've isolated this to being outside my home network (local hub ping is clean, only external destinations are affected), how could I get someone take a look at whether there's congestion, a routing issue, or a problem on my local exchange/backhaul? Given it's intermittent, a single point-in-time test won't catch it; would it be possible to run extended monitoring on my line, or check BT network logs for congestion events?

Happy to provide exact spike timestamps if that helps cross-reference against monitoring, also happy to be proven incorrect if I have ruled out anything that could still be affecting it and is within more of my control.

[Peter_W]

Thanks for taking the time to highlight these issues, @Cianito 

Congestion would usually be down to increased traffic on the network, are you noticing these latency spikes specifically at peak times, or can it happen at any time of the day?

Could there also be the possibility another device on your network, is causing increased strain on the connection?

It could even be something in the background on your PC - I've noticed sudden lag issues when gaming in the past, and it's been due to multiple Steam updates going on in the background.

Also just to rule this out as an issue, have you tried swapping out the ethernet cable between your Hub and the ONT?

Peter

[Cianito]

Hi Peter, thanks for the reply.

Timing: Yes, mainly from the morning to the evening, the issue is mostly absent at night.

Other devices: I tested this after disconnecting and turning off every other device in the house and running with an ethernet connection and the issue still kept happening. From the ping tests I did on both my laptop and a playstation 5 it seems to be affecting general external connectivity.

ONT test: Tried this, the issue is still occurring in the same way. 

Given it's prevelant during daytime hours, is there any way to check if my area is near capacity or if there's work planned/being done that might be causing issues?

[Peter_W]

Cheers @Cianito.

I'd like to grab a few more details so we can feed this one back, so I'm going to pop you over a private message.

Speak soon,

Peter