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Weird: slow speed from US only on Windows only

Vadimenator
Tuning in

Hi, just got Virgin broadband installed and ran a strange problem with download speed. On Windows laptops only download speed is terrible for US sites, but fine for UK ones.

Windows:

- SpeedTest for a California server is 10-20Mbits/s, for London servers 350-390

- Download from Skype or Ubuntu is at around 4 MBytes/s

iperf3 to the US server 3.25 Mbits/sec, to France 25.6 Mbits/sec

Windows via NordVPN:

- SpeedTest to the same California server is 300 Mbits/s (apparently, limited by the VPN performance only)

Ubuntu or Android:

- honest 350Mbits everywhere

What I've tried so far:

- connected with a cable instead of WiFi

- updated all drivers

- reset Winsock 

- Disabled QOS driver

- changed DNS to Virgin's one

- tried to change the TCP congestion control algo, but looks like it's impossible in Windows Home.

Also I've noticed that all downloaded files have wrong timestamps now, around 2007 (no, Windows time is correct).

What's suspicious, I had a very similar problem with slow US download speed on Virgin few years ago, in different home, with different laptop, different router, so the only common element in these pictures is Virgin. Overall, looks like a broken packet inspector or traffic shaper to me.

I'm still within two weeks window to cancel my contract and going to exercise this right if I don't find the solution to this.

7 REPLIES 7

Laurie_C
Forum Team (Retired)
Forum Team (Retired)

Hi Vadimenator,

 

Thanks for getting in touch, and a very warm welcome back to the Community Forum. I'm sorry that you're having some issues with slow speeds.
 

I've had a look at your account, and I can see that everything looks okay from our end. All of your levels are within specification, and there aren't any known issues or outages in your area.

 

Would you be able to run a speed test on https://www.speedtest.net/ using a wired connection?

 

Kind regards,

Laurie

Laurie_C
Forum Team

Zoie_P
Forum Team (Retired)
Forum Team (Retired)

HI Vadimetnator, 

Thanks for your reply, 

you need to run a standard speed test and not manually, you do not need to change the server.

I can see a few issues with some devices connected on the 2.5ghz are having issues as it is at capacity.

Zoie

Hi Zoie,

thank you for looking into this. The problem is slow download speed from US, so I have to change SpeedTest server to test it. For London servers the speed is OKish as it's 350 during the day and around 200 in the evening.

Regarding 2.5G WiFi - my PC is connected with a cable so WiFi is not a concern.

Thanks,
Vadim

Adduxi
Very Insightful Person
Very Insightful Person

Looks like you should be doing traceroutes to determine where the connections are being routed.  Have you tried Modem mode with just the single windows laptop connected? Modem mode will get a different WAN addresses to Router mode and may take a different route out.

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Hi @Vadimenator

Forgive me, but is there anyway of testing if those websites, the US based ones, run slow from other networks?  Sorry I'd like to determine if it's our network or the website itself.

Regards

 

Lee_R

Hi Adduxi,

thank you for your suggestion. I'm afraid, in modem mode the route is exactly the same as well as the speed. Looks like very subtle TCP/IP issue, like this one https://www.ispreview.co.uk/index.php/2020/09/quick-update-for-virgin-media-speed-issues-on-ipv6-tun.... E.g. congestion control algorithm going crazy on a high latency connection.