Netflix quality degraded with Vodafone but not BT

[angrydave]

Hi all,

I have 2 connections, one with Vodafone and one with BT.

Streaming HD content from Netflix via Vodafone results in at best about 1-5 - 2Mbps bitrate at 720p. The same content via BT results in 5Mbps+ at 1080p. The quality is visibly poor with Vodafone and crisp with BT. I'm streaming from the same device, connected via ethernet, just switching the cable between routers. 

Both connections have a sync rate above 73Mbps and get 70Mbps+ on a multi-connection speed test, however Vodafone only gets around 28-38Mbps on a single connection speed test whereas BT gets around 50-70Mbps. 

The lower single connection speed test result shows that Vodafone is more congested than BT however the result should be plenty for a 1080p HD stream, or even a 4K stream.

Is anybody else experiencing this?

Is Vodafone prioritising speed test results to disguise 'true' network performance which is perhaps suffereing from the increased demand due to COVID? Does Vodafone have a peering issue with Netflix (though you'd expect them to have a local cache)?

Something is clearly going on as this has been happening for days now.

Thanks for reading,

Dave

[Anonymous]

Hi @angrydave, how odd! Does this happen at specific times of day, or consistently? Are any other streaming sites or web pages affected in the same way?

[angrydave]

I've done some experimentation since I first posted. 

I thought that perhaps my homeplug devices were interfering with the VDSL signal, however putting them in 'low interference mode' made no difference at all.

Out of frustration I reset the Vodafone router to defaults and then re-made all configuration changes manually (e.g not reloading the saved configuration file) and so far, Netflix is working just fine with the same bitrate and quality as on the BT connection.

I'll be keeping an eye on things but so far it looks to have been an issue with the router, which was solved by performing a factory reset.