Thank you both for the explanation.

In reply to a post by oldskool:

Thank you both for the explanation.

No probs, basically all ONT's connected to those 32 split fibres all receive the same data, but only the ONT that the data is for can decrypt it.

Image of the Passive Optical Network (PON) the bottom section of the image.

Passive is good due to no power required.

Paul

In reply to a post by techguy:

Is there any reason why Openreach/Wholesale FTTP is Asymmetric (other than protection of a profitable leased line business)?

The reason it's as asymmetric as it is is entirely commercial. Upload speeds could be 50% those of downstream.

In reply to a post by Pheasant:

I was led to believe that Openreach were going to introduce some symmetric FTTP plans this year, but the plan was shelved after COVID-19 hit.

No idea what price they were going to pitch it.

Not sure about introducing plans but certainly trialing the technology to support it, which they are.

XGSPON.

Would be at 'business' pricing so within the range of serious enthusiasts / home office users.

In reply to a post by PaulKirby:

Its all down to what is at each end, (i.e. the Exchange and and ONT) so if you change the hardware at the exchange to do 10Gbit the ONT will need to be upgraded to handle that speeds.
However I think the XGS-PON can and does support both 1Gbit / 2.5Gbit and the 10Gbit so the Exchanges could already of been upgraded but just running at the lower speeds.

Just FYI XGSPON is not backwards compatible with GPON. Need to at very least change optical modules in the line cards in the OLT if using Huawei Flex-PON or similar and most likely change the entire board as you can get twice as many GPON ports out of a standard GPON board as XGSPON ports out of an XGSPON board.

I imagine it'll initially be built with both GPON and XGSPON OLTs feeding an area, combined and split at the exchange and traveling down the same fibre from there, with XGSPON introduced as needed.

Could certainly get 1000/500 out of GPON and overlay with XGSPON as capacity relief when needed so really no rush for Openreach to get XGSPON kit into exchanges or cabinets just yet.

In reply to a post by CarlTSpeak:

Not sure about introducing plans but certainly trialing the technology to support it, which they are.

XGSPON.

Would be at 'business' pricing so within the range of serious enthusiasts / home office users.

Pre-COVID lockdown around early March I was looking at FTTP plans to migrate to when my oD contract finished in July. At the time my provider said there were going to be symmetric plans available possibly in the timescale I was looking into. A month or so later, post lockdown etc, I was told those plans were shelved, for this year at least...

As to the cost, anyones guess but I'd imagine sandwiched somewhere between the top of the asymmetric plans and lower end of leased line so probably somewhere around £200 pcm before VAT I would hazard a guess.

In reply to a post by Pheasant:

Pre-COVID lockdown around early March I was looking at FTTP plans to migrate to when my oD contract finished in July. At the time my provider said there were going to be symmetric plans available possibly in the timescale I was looking into. A month or so later, post lockdown etc, I was told those plans were shelved, for this year at least...

As to the cost, anyones guess but I'd imagine sandwiched somewhere between the top of the asymmetric plans and lower end of leased line so probably somewhere around £200 pcm before VAT I would hazard a guess.

Symmetrical by July was always pretty unlikely. The initial XGSPON testing is only relatively recent and of a small scope. Openreach would've published details of XGSPON pilot availability on their various platforms.

FWIW there are companies on symmetrical FTTP via XGSPON on the Openreach network right now. It'll also be used as capacity relief when GPON becomes an 'issue'.

Yes I agree July would have been pushing it, but the impression I had at the time was "this year" perhaps not necessarily July though. Anyhow it's rather academic as all bets are off on that for 2020 at least it would seem.

Perhaps with no more unforeseen interruptions to business and life at large, we will see Openreach offer symmetric plans by this time next year...

From what I understand, GPON and XG-PON use different light wavelengths at 1480-1490nm and 1574-1584nm respectively, so you can use the same fibre, just with different lasers on each end.

Then there's XG-PON1 (asymmetric) or XG-PON2 (symmetric), and then there's NG-PON2 which uses yet more wavelength blocks to aggregate between splits and is effectively 4x XG-PONs all using different wavelengths on the same fibre, but getting 4x the aggregate throughput...

GPON and XG-PON can operate on the same fibre at the same time by using wavelength division multiplexing (WDM) in the exchange and ONT's already contain a wavelength filter.