This topic

FTTP with a 3rd party router - Speed Issues

ripface — Fri, 26 Jun 2026 18:31:43 GMT

Hi All,

I recently moved into a property with FTTP and was looking forward to lightening fast broadband. As I've been an ASUS router user for some years I just ignored the BT SmartHub 3 and plugged my trusty RT-AX82u into the focom and away she went. However checking the speeds revealed a disappointing 80-90 mbps when I'm paying for 500mbps.

I reported this to BT but they will not do anything as I'm not using their router. I like the ASUS as I can protect the entire house with VPN client, something the BT Smart (?) hub cannot do.

To check how the Smart Hub 3 performed I plugged it in ... and immediately started seeing speeds of around 400-450 mbps. Went back to Asus and it drops now to around 200 mbps. Better than I was seeing but not quite up to par.

Anyone know if there are settings on the Asus router that will get it working as well as the BT Smart Hub 3?

Cheers,
Ripface

Re: FTTP with a 3rd party router - Speed Issues

licquorice — Fri, 26 Jun 2026 18:41:06 GMT

Suspect the Asus is simply past it's sell by date and not up to the job. BT only guarantee speed to the the ONT, not to the end device.

Re: FTTP with a 3rd party router - Speed Issues

WSH — Fri, 26 Jun 2026 18:48:07 GMT

It could also be pushing everything through a VPN, so it has to go through a third party server and then be rerouted to its final destination. Frankly, now all internet traffic is encrypted with HTTPS, encrypting the traffic twice is just inefficient.

Re: FTTP with a 3rd party router - Speed Issues

ripface — Fri, 26 Jun 2026 18:53:09 GMT

Good point, but I still prefer to use VPN for other reasons that just security ......

Can you recommend a more performant router that might be better? I guess the Asus RT-AX82u is a little behind the times!

Re: FTTP with a 3rd party router - Speed Issues

WSH — Fri, 26 Jun 2026 18:56:41 GMT

Your reference to 80-90Mb/s also smacks of a connection issue. If one pin out of the 8 is not connecting the best you’ll achieve is 100Mb/s.

Are you using the same cable as the Smart Hub or a different cable? If so, I’d try the other cable.

Re: FTTP with a 3rd party router - Speed Issues

ripface — Fri, 26 Jun 2026 20:06:42 GMT

Thanks for the input, but different cables did not make any difference. Strangely since I've put the Asus back in operation it seems to be working a bit better as I'm now seeing ~200mbps with the VPN switched on.

Re: FTTP with a 3rd party router - Speed Issues

WSH — Fri, 26 Jun 2026 20:24:31 GMT

After the last few days it could be an overheating issue causing the processor to throttle.

Re: FTTP with a 3rd party router - Speed Issues

ripface — Fri, 26 Jun 2026 21:16:33 GMT

Overheating? Yeah, I'm in NE Scotland ... been a bit warmer but not *that* warm!!

Thanks for the suggestion though .....

Re: FTTP with a 3rd party router - Speed Issues

WSH — Fri, 26 Jun 2026 21:37:35 GMT

How old is that Asus? I’ve not checked, but as Licquorice suggested, it might not be up to the job.

A lot of the pre-full fibre generation of routers had firewall through-puts limited to 350Mb/s sort of region. Afterall, back in the day 80Mb/s was the best broadband connection you could get. Even if it had gigabit ports, they were more to service the internal network traffic than the internet connection.

Re: FTTP with a 3rd party router - Speed Issues

gg30340 — Fri, 26 Jun 2026 21:48:51 GMT

Your router VPN will cause at least 10% to 20% loss in speed and often even more if it is a free VPN.

The speed can be affected by where the country is that the VPN servers are using because the "traffic" has to travel there and then to the site that you want to see then then back to the UK.

It can also be affected by the load on the VPN servers where more users equals slower speeds.

If your router's VPN is not a subscription VPN it will have a relatively low number of servers for "free" customers. which will affect the speeds because the servers can become over loaded.

Because your speeds are vastly improved to what they should be when you use the Smart hub 3 it would point to the problem being your Asus router and as you have found out BT will not help when you use a 3rd party router.

I would say that you are better to have a VPN on each device and only use it when necessary rather than a router based VPN which is slowing all your traffic all the time..

Re: FTTP with a 3rd party router - Speed Issues

shakey1981 — Sat, 27 Jun 2026 11:06:42 GMT

plug the bt hub in test the speed

plug the asus in then check with vpn off

Re: FTTP with a 3rd party router - Speed Issues

TimCurtis — Sun, 28 Jun 2026 15:31:00 GMT

I run an Asus RT-AX5400 which is virtually the same as the RT-AX82u internally and I have no issue with my 500/500 service - not BT obviously. It runs an AIMesh network and any of my wifi 6 devices can hit 300+ easily. Hardwired I get my full 500/500.

I have access to 3 VPNs - Kaspersky, Oyster & Windscribe. Just done some quick speed tests & Kaspersky & Windscribe on UK sites have little effect on speed but Oyster slashes it by more than 50% so could easily be a VPN issue.

Re: FTTP with a 3rd party router - Speed Issues

TimCurtis — Mon, 29 Jun 2026 07:08:20 GMT

Just to add that the above tests were using a VPN on my PC which might not be relevant so I added my PC to my VPN Fusion setting for Windscribe so running my speedtest through my router's inbuilt VPN facility as I think the OP would be doing and got exactly the same results so the router is more than capable.

So @ripface what VPN are you using?

Re: FTTP with a 3rd party router - Speed Issues

ripface — Mon, 29 Jun 2026 09:19:34 GMT

Thanks for that, I'm considering a factory reset to see if that helps. Bit of a **bleep** as I've quite a lot of customisation in there. Cheers!

Re: FTTP with a 3rd party router - Speed Issues

WSH — Mon, 29 Jun 2026 09:50:54 GMT

You should be able to export the configuration settings and then reimport them after the reset.

Re: FTTP with a 3rd party router - Speed Issues

ripface — Mon, 29 Jun 2026 10:33:27 GMT

As long as that process doesn't restore the settings that might be causing the issue .....

Re: FTTP with a 3rd party router - Speed Issues

WSH — Mon, 29 Jun 2026 12:38:35 GMT

It doesn't usually if it's a glitch that's developed with the router over time but it's possible. Of course, if you typed the settings back in by hand you'd be in the same situation.

Up to you either way. Just thought the info may help if you were unaware of it.

Re: FTTP with a 3rd party router - Speed Issues

TimCurtis — Mon, 29 Jun 2026 16:05:14 GMT

@ripface

You haven't said which VPN. If it's OpenVPN then that would certainly explain speed issues as I've found it slower than others.

Just do a Save Settings & then press in the reset button for 10-20 seconds. Shouldn't be any issue with reloading the saved configuration leaving you exactly where you were before but refreshed. The only issue sometimes is with the Asus DDNS name as that can fail to reload but if you don't use it then no problem. I think it unlikely to help though.

One thing that's often been a problem with Asus is the use of QoS as that has sometimes affected speeds. You haven't got any restrictions set have you?

Re: FTTP with a 3rd party router - Speed Issues

TimCurtis — Mon, 29 Jun 2026 16:20:43 GMT

@ripface

Why don't you turn off the VPN in VPN Fusion (presumably) and run a speed test within the Asus. That should give you some pointers as to what the issue might be.

Re: FTTP with a 3rd party router - Speed Issues

ripface — Mon, 29 Jun 2026 16:23:06 GMT

Hey Tim,

Yea, tried that and see around a 10% difference with VPN off. It's a wireguard protocol with incurs the least overheads with VPN. Still doesn't account for the poor performance of the RT-AX82u.

Cheers,
John.