FTTP ONT Speed Problems - reboot appears to resolve ?

Hi,

I've been on Sky FTTP 150Mb service for a few months and recently noticed with various speed tests and more accurately newshosting multi threaded downloads I was never getting more than 80Mb/s - note I am fully wired ethernet, not WiFi.

I rebooted my 3rd party router (Netgear running Openwrt) and didn't see any improvement, so powered ONT and router off and reconnected Sky router - I then saw 150Mb/s speed within 30 mins.

Bit weird I thought, so reconnected my 3rd party router and still speeds are good.

Now a few weeks later notice I have the same problem again with never going above 80Mb/s, just power cycled my router but still issue remained.

So, rebooted my ONT and within 30 mins speeds back up to 150Mb/s.


This implies rebooting the ONT is resolving the issue (for a period of time) - anyone had this issue or know what could cause it?

Thanks!

Before you call up Sky to get Openreach to replace the ONT (fairly sure this is it), try replacing the Cat5e/6 fly lead between the ONT and the router with a fresh new lead.

Sorry forgot to mention I swapped the CAT5 lead between ONT and router when I tried the Sky one.

Thanks for your insight, I will wait to see how long it runs at 150Mb/s before dropping again and definitely prove again an ONT reboot resolves it - don't relish having to explain to Sky technical support ....

Just seems weird, I would have thought the ONT woudl either work or not - didn't know if there were FTTP "speed profiles" like VDSL2 and maybe I was for some reason getting moved to a slower one.

It’s worth trying the basics first 👍

There are definitely speed tiers / profiles on Openreach FTTP. Seventeen to be precise. However they are provisioned by the system when the ONT first powers up/is rebooted. They don’t dynamically alter on the fly or “retrain” based on line conditions or any copper-based broadband concepts like that.

This is unusual for FTTP. Worth getting Sky to check you FTTP provisioning speed/profile matches what you ought to be getting and explaining what is occurring with the fault.

Sounds to me this could this just be randomness of connecting to different gateways? So just a coincidence you happened to land on a less congested gateway after rebooting the ONT, this led you to believe the ONT has a problem when it might not.

If it happens again, rather than reboot the ONT, get your router to drop and reconnect a few times testing the speeds. You should be able to see the gateway IP address in your router settings somewhere, and can see if when that changes it correlates to changes to your speed test results.

Edited by E300 (Thu 10-Feb-22 08:53:10)

I don't know how it works at that level.

If it is a "gateway" issue then this implies I am getting switched to different gateways without me actively doing anything OR the one I am on degrades in speed badly and stays like that - wouldn't multiple people be affected by a congested gateway?

And by chance when I reboot the ONT I always get on an uncongested one...



For now I think I will keep monitoring and see how long it stays on 150Mb/s.

I do think "never going above 80Mb/s" and a reboot of the ONT fixing it is significant.

I am talking purely from a layman's point of view so I would give Sky a call and make it their problem to fix it if it reoccurs.

In reply to a post by starfire:

I don't know how it works at that level.

If it is a "gateway" issue then this implies I am getting switched to different gateways without me actively doing anything

Yes. If it's PPPoE, there's a "discover" phase and multiple BRASes may offer service.

In reply to a post by starfire:

OR the one I am on degrades in speed badly and stays like that - wouldn't multiple people be affected by a congested gateway?

Yes to that too.

In reply to a post by starfire:

And by chance when I reboot the ONT I always get on an uncongested one...

That's what seems to suggest it's not the problem. Equally, restarting the router without touching the ONT should be able to switch you between BRASes.

Does your router have any sort of interface monitoring? Can it tell you whether its WAN port is running at 1000/1000 or 100/100? A bad cable or a bad port on the ONT or router *could* cause the ethernet connection to drop down to 100/100. It has been known to happen, so it's good if you can rule it out (i.e. if you can see that the WAN port is definitely 1000/1000 when the speed is slow).

In reply to a post by dect:

I do think "never going above 80Mb/s" and a reboot of the ONT fixing it is significant.

I am talking purely from a layman's point of view so I would give Sky a call and make it their problem to fix it if it reoccurs.

Except the problem so far is only reported with the third-party router, and putting the Sky router in place has fixed it. (Aside: OP should make sure they don't touch the ONT in future when doing that).

And of course, Sky will say it's the third-party router which is at fault. Which it certainly could be.

In reply to a post by candlerb:

Does your router have any sort of interface monitoring? Can it tell you whether its WAN port is running at 1000/1000 or 100/100? A bad cable or a bad port on the ONT or router *could* cause the ethernet connection to drop down to 100/100. It has been known to happen, so it's good if you can rule it out (i.e. if you can see that the WAN port is definitely 1000/1000 when the speed is slow).

Yes, I can see the WAN link up at 1000Mbps full duplex. I have already tried a different cable.

But will monitor it.