FTTP 900 but strange download speeds.

[mikemod]

So I signed up for FTTP 900 a few months back.

What I am noticing is that a lot of sites, including Microsoft, seemed to be limited to about 200Mbps download

I also noticed that if I enable a VPN on my PC, NordVPN,   the speeds are close to the 900Mbps.

Here is an example download from the the same site.

VPN off, around 300Mbps

The same download from the same site with VPN enabled, speeds around 800Mbps as expected.

All the speed tests, including the BT Wholesale one, report about 900Mbps

Are BT doing traffic management on certain sites?

If that is the case it seems pointless paying for anymore than the 500Mbps package.

[BuzzLightyear2022]

Seems more than likely either a transit or peering capacity issue rather then traffic management

Is really Interesting to see your getting close to 900Mbps via BT Wholesale as this is hosted via Akamai CDN.

Have you tired https://www.thinkbroadband.com/speedtest
and also www.fast.com (Uses BT Netflix CDN)

[mikemod]

Speed tests using fast.com are consistently 900+

Thinkbroadband speed tests give much more consistent results using the VPN.

Result using VPN

Result with VPN disabled

The tbbx1 test is much higher through the VPN.

With the VPN enabled, things like Windows Updates are nearly at full speed.

[mikemod]

I did a trace route on google.co.uk and notice after my router the next hop is to a 172.xxx.xxx.xxx private address

Is this just some internal BT equipment or the ONT?

[licquorice]

It's the BRAS

[BuzzLightyear2022]

There you go then, It honestly sounds like a peering/transit capacity.issue.If you getting 900+ with fast.com is basically cached via BT CDN servers rather then routing over.

Far as i know, My Microsoft xbox downloads via EdgeCast CDN or Limelight CDN but even coming from Zen myself to BT in the last month is still the same CDNs however i cant say how fast i can download as im on FTTC and only synced 69/18 but with my xbox downloads all i can say it various on speed.

Even if you wonted to downgrade to 500Mbps package, BT might not let you as you can hit 900+ on fast.com so is clearly a peering or transit capacity issue.

The only way to get around this would be to join another ISP thats premium range such as AAISP yet pricey but would certainly get what you pay for.

Remember VPNs will use different route then BT's as with a VPN, It uses the server to route your traffic around.

172.x  belongs to BT network.

[licquorice]

The 172 address doesn't belong to anybody, it's a private non routable IP address not a public one. It is however, used by BT as the link local address of their BRAS as already stated.

[mikemod]

So I have now installed the VPN on my home router so the whole house goes through it.

Everything is now running at near full speed, Steam and EA downloads are now 700+

It seems strange that BT sell a 900 product but their network can't support it

I was offered it at an extra £1 per month over the 500 so I will just leave it and use the VPN

[0x_0]

Seeing exactly the same thing here. Getting 400-500 normally, and 900+ on a VPN.

When I try download ANY game (Steam, Epic, etc...) I get some form of 50mb/s cap on my entire bandwidth. It appears almost the instant I start the download, and speeds will return a minute or so after stopping the download. 

[mikemod]

After some advice I decided to try Ubuntu instead of Windows and it works perfectly, no VPN required

Downloads are at maximum speed, just downloaded the Windows 11 ISO from Microsoft @ 100MBps  🙂