FTTH install with Gigaclear - "optic loss" and speeds

Hello,

I've just had FTTH installed at home, despite me not actually being there! I signed up for Gigaclear in December and they've finally got round to installing. Luckily, my brother lives in the house until this whole pandemic is over.

Anyway, I notice on the install sheet it says "optic loss -8" and POT to "CDC distance" is 375m.

D/l : 211Mb/s
U/l : 174Mb/s

As someone going from 3.5Mb/s FTTC, this is obviously great, but I am paying for 300Mb/s, so I was expecting a bit more. As I wasn't there to ask any questions, does anyone know if these "optic loss" and CDC distance figures are a concern for reaching more than the 211Mb/s d/l speeds they've apparently achieved on install? Could it just be the speedtest servers they use were busy (I would like to think they have their own and don't rely on, say, speedtest.net)

Thanks,

Steve

‘optic loss’ sounds like a Gigaclear name for a light loss reading. On Openreach FTTP the reading should be between -15db and -25db

Since their set up is clearly different, I’ve no idea what their parameters are.

The second figure may be distance between the light source (splitter/headend/whatever they call theirs) and the property.


In terms of speed tests, please ensure all are carried over an ethernet connection to the router, and that the laptop/PC is of a good standard.

Thanks for that, I'll try to do some research and see if Gigaclear -8 is at all comparable with the -15db and -25db that you mention for OpenReach FTTP installs.

(Just to be clear, the figures I gave for the u/l and d/l speeds were from Gigaclear themselves on their install sheet, so I'd hope they used wired equipment capable of checking up to 900Mb/s!. I'll try when I can on a wired gigabit ethernet connection and then possibly take it up with them).

Edited by deleted (Tue 09-Jun-20 18:06:01)

At least you got it installed. There’s a lot of areas round here where they have the network in the ground, but some mysterious issue is stopping them being able to provide service. The usual story I hear is that Gigaclear need agreed access to some railway land or summat.

It hasn't been smooth with them. They are 18 months late and once it was installed - the POTs on the verge and everything - I signed up in December, with an install date a couple of weeks later. Only to then be told there was a break in the fibre somewhere. Anyway, it's now 6 months later and it's done.

In the meantime, County Broadband have finished laying their cables (mostly on the phone lines) so now in a bizarre position of having two different fibre lines available to the house. Stuck with Gigaclear though. After having 3Mb/s for years (and 1.2Mb/s on the old ADSL service before that), it's finally done.

Still, my first modem was 1200/75 with Prestel, so I admit things have improved slowly.

In reply to a post by splatt:

Anyway, I notice on the install sheet it says "optic loss -8" and POT to "CDC distance" is 375m.

D/l : 211Mb/s
U/l : 174Mb/s

As someone going from 3.5Mb/s FTTC, this is obviously great, but I am paying for 300Mb/s, so I was expecting a bit more. As I wasn't there to ask any questions, does anyone know if these "optic loss" and CDC distance figures are a concern for reaching more than the 211Mb/s d/l speeds they've apparently achieved on install?

The optical loss figure is not a worry. FTTP either works or it doesn't; it's not like FTTC where there is rate adaptation, and the speed varies with the length of the copper.

Are those D/l U/l speeds measured by you, or recorded by Gigaclear themselves on install?

Whether you achieve a given speed with a speed test, at a given time of day, depends on a whole range of factors. You'd think Gigaclear would try to make their speed tests as high as possible (e.g. by hosting their own speedtest endpoint on their own network), but maybe they were just testing to some random site on the Internet.

Zarjaz - If the figures fall far outside of that range will it just cause the connection to go on and off? It wouldn’t cause it to be slower would it? I don’t know as I was never trained to fault it.

I was told you're fibre can get "dirty" and reduce the speed that it operates at.

Well according to the guy fitting mine anyways.

If it were right on the borderline, you might get some data through and some lost, and packet loss causes TCP to slow down.

It's like digital TV: normally you'll either get a good picture, or no picture. However right at the boundary, you might get a picture with digital splats.

FWIW, -8 dBm is a strong optical signal. I see -5 or -6 as the transmit and receive levels measured by SFPs in data centres.

If you for example unplug the fibre from the ONT and leave it open to air you will get dust and other particles on it this can recreate light loss and eventually the ONT will just moan not enough light.

There is a point where ONT might hover between enough/not enough lift and so you may see a flicker between link and no link with the errors that creates.

Light loss is measured by kit and can be monitored.