Full Fibre 900 intermittent packet loss on the BT network side (connection never drops), line test

MFlex — Thu, 18 Jun 2026 11:57:49 GMT

Hi all,

I'm hoping a moderator can help get a network-side fault investigated, as standard support has been unable to identify the issue and repeated line tests are coming back clear.

Service

BT Full Fibre 900 (FTTP)
Smart Hub 2
ONT connected directly to Smart Hub 2
Mixed wired and wireless devices

Issue

For several weeks I've been experiencing intermittent packet loss to the internet, typically between 1% and 6% in bursts. It is most noticeable from mid-afternoon into the evening.

The connection itself remains established throughout. This is packet loss rather than a loss-of-service issue.

The impact is noticeable across video calls, online gaming and streaming, and affects all devices regardless of whether they are connected via Ethernet or Wi-Fi.

Troubleshooting completed

I've been running continuous monitoring and have ruled out my internal network:

0% packet loss within my own LAN, including to the Smart Hub.
Packet loss only begins once traffic leaves the hub and enters the BT network.
The first BT hop beyond the hub shows loss during the affected periods, and the same loss is visible to multiple external destinations.
IPv4 and IPv6 experience packet loss at exactly the same times, suggesting a common issue on the shared network path rather than a problem with any specific service.
No disconnections are recorded in the Smart Hub event logs during the affected periods.
The broadband session remains established throughout.
Packet loss generally worsens during peak hours, increasing through the afternoon and evening.
As this is FTTP, the issue does not appear related to copper line conditions or DSL synchronisation.

Why line tests are not identifying the issue

The line tests appear to confirm that the connection is active, which is expected because the service is not dropping. The issue is intermittent packet loss rather than a loss of connectivity, so a snapshot test does not appear to capture the fault.

Request

Could a moderator arrange for this to be reviewed by the appropriate network team as an intermittent fault requiring monitoring over time rather than a single point-in-time test?

I'd be particularly interested in having the following checked:

Errored seconds and packet discard counters on the serving OLT/access port
Optical receive power levels on the FTTP circuit
Any known congestion, capacity constraints or utilisation issues affecting the serving OLT, exchange or aggregation network

I have ping logs, traceroutes, timestamps and loss trend data available and would be happy to provide them if required.

Thanks in advance for any assistance.

Re: Full Fibre 900 intermittent packet loss on the BT network side (connection never drops), line te

MFlex — Thu, 18 Jun 2026 11:58:40 GMT

I got in touch via live-chat and they just tried to upsell me WiFi range extenders to solve a problem experienced on ethernet 😭

Re: Full Fibre 900 intermittent packet loss on the BT network side (connection never drops), line te

Christopher_G — Fri, 19 Jun 2026 16:07:03 GMT

Hi @MFlex

Welcome to the community.

I'm sorry to hear that you're having some issues with packet loss. The best thing you can do is speak with our technical support team over the phone. They're in the best position to run through diagnostics and escalate it further, if they're unable to fix it over the phone.

If you're unhappy with how things are progressing, I recommend following our complaints process and our team will do their best to find a solution for you.

Please keep us updated with what happens.

Chris

This topic

Full Fibre 900 intermittent packet loss on the BT network side (connection never drops), line test

Service

Issue

Troubleshooting completed

Why line tests are not identifying the issue

Request

Re: Full Fibre 900 intermittent packet loss on the BT network side (connection never drops), line te

Re: Full Fibre 900 intermittent packet loss on the BT network side (connection never drops), line te