Latency - CityFibre

Hi all, I'm fairly new to Zen. I moved from BT because OpenReach are not planning to support fibre to my house but CityFibre do.

One thing I've noticed is that occasionally the latency (as measured by BQM) will jump to 15-20ms and stay that way until I toggle the power to the ONT. It then returns to 6-7ms.

This doesn't appear to cause any issues but it would be nice to keep the lower latency for gaming etc.

Is this a Zen Internet thing? Should I consider a different CityFibre ISP or is it a CityFibre thing?

My only other option for fibre is VM, and I'd really rather not go there based on prior experience with them.

Its a Zen thing that will probably also happen if you OR FTTP via Zen. They load balance across their different locations.

The problem should go away if you use an ISP that only terminates in London.

Thanks. Guess I'll have to search around a bit more on my next renewal.

Hi bud Just a few quick questions first.Then hopefully I will try to be able to help.
What speed service are you paying for?
How long have you had the City Fibre internet installed for first?
Secondly how long have you had the ONTt online and powered on working?
What internet speed are you paying for what router are you using to connect to the ONT specifically the make model?
Also what speed of LAN ports are you using to firstly connect to the ONT then secondly to connect to the PC in question?
Along with what speed is the network card on your PC?
Next what type of LAN cables are you using specifically what generation i.e. cat 7 cat 5 etc?
What length of network cables are you using?
Also what tests have you done to see if you can fix this?
I am on Cityfibre's network going through a company called the One broadband I am paying for a 2.2 Gb internet service.
The ONT is connected to my ROG Rapture GT-AXE16000 router the ONT is connected to the router using the 2.5 Gb Wan port.
Then the PC that I use is connected to the router on a 10 Gb LAN port connected to my PC using a 10 Gb network card I am using cat seven LAN cable for connecting my PC to the router and it's under 5 metres in length
Please let me know buddy and I'll see what I can do

Edited by tom01793 (Tue 27-Jan-26 02:15:34)

Thanks for the offer of help but most of what you are asking is irrelevant. My CityFibre connection for Zen Internet was installed last September, the 900Mbps option. It is the Zen Internet provided router (fritz box 7530 ax) that responds to the thinkbroadband BQM pings, they don't go onto my home network. The length of time before a jump to higher latency is variable, could be days or weeks. Restarting the ONT resets the latency for a while.
As Chrysalis already stated, this is something I'll have to live with until I change to another ISP.

In reply to a post by Chrysalis:

The problem should go away if you use an ISP that only terminates in London.

Which ones?

I've just got notification that I can get FTTP over Openreach. Currently we're with Zen FTTC (LLU), but the latency of Zen over Openreach isn't particular attractive.

So I'm brainstorming options.

In reply to a post by ohit:

Which ones?

As far as I know Zen are the only provider that do this ridiculous gateway load balancing exercise without any consideration of where the subscriber is physically located.

In reply to a post by jpm:

As far as I know Zen are the only provider that do this ridiculous gateway load balancing exercise without any consideration of where the subscriber is physically located.

How annoying. I've basically been with Zen since 1999 and hadn't paid much attention in that time. They were always considered one of the better providers.

Which FTTP Openreach provider I go with now is the question. I thought IDnet but they too sometimes use Zen and therefore same routing issue.

PlusNet/BT/EE, Sky, Vodafone - I need to do more research, but I suspect these are not unrestricted providers (e.g. providers like Zen, A&A, etc. all openly believe in unrestricted/unblocked Internet without any site or DNS filtering).

Any suggestions on FTTP provider over Openreach with South/East London termination (physical first hop location) ?

The gateway change happens when PPPoE is dropped or the router restarted, nothing to do with the ONT.

As mentioned, any ISP not using the Zen network should not have this problem, assuming it IS the gateway issue.

Pretty sure I heard of CityFibre having their own latency quirks though, I could be mistaken?

The two known ISPs on CityFibre to have latency weirdness is Zen and Vodafone, who both use regional handover points.