PON for the Office / Home

Does this exist - the use of PON technology in the office or home?

Seems like it is ideally suited to the office with many workstations.

Edited by Eeeps (Fri 20-Dec-24 14:04:33)

I'm confused as to what benefit this bring over fibre or cat6 capable solutions

In reply to a post by Taras:

I'm confused as to what benefit this bring over fibre or cat6 capable solutions

Point to multi-point.
Reduction in cable requirements.

Also, remote switch stacks can potentially be removed with a few fibres direct to coms rooms.

In reply to a post by Eeeps:

Seems like it is ideally suited to the office with many workstations.

Many offices have gone WiFi for end user compute, and ditched telephones, so only mains electricity cabling required. In data centres, 25 GigE over copper is easy at managed distances. Point-to-point fibre has been around decades, for your front end network and for your data network (e.g. SAN).

The benefits of a PON are where you have geographical range to cover, such as a town, so that its not something I can see a reason to go with. Shared bandwidth is always worse in a data centre.

In reply to a post by Eeeps:

In reply to a post by Taras:

I'm confused as to what benefit this bring over fibre or cat6 capable solutions

Point to multi-point.
Reduction in cable requirements.

Also, remote switch stacks can potentially be removed with a few fibres direct to coms rooms.

I've seen various organisations attempt fibre to the desk over the years, and it never succeeds. Usually one person in the organisation has a pyrrhic dream...reality soon dawns.

Generally offices use a fibre backbone to switches that are local to the users (and in a wider basis fibre to connect WAN sites). It isn't dissimilar - fibre comes into the building then into a fibre switch which then takes fibres to the local cabs where copper is generally used to deliver to the device.

Copper is much easier to run in an office and connects straight into end device network ports.

And as someone else said more and more moving towards WiFi first so far fewer cables to end devices - the cabled end devices generally being the wireless access points, fixed desktops and printers.

PON solves a different problem than exists in an office though - office fit outs put the money into raised floors and cable trays so that adding another five data outlets can be done in a couple of hours after people have gone home, and the tools to terminate Cat6 cable are cheap and require very little training to use. PON is designed to keep cabling in limited capacity ducts to a minimum which isn't a problem in a cable tray under a floor.

If you built an office using PON then you either overprovision and waste money, or you have to light up a new OLT port to add one additional user. You also have to come up with a way to power IP phones and access points. I'd be surprised if the OLT and ONTs to support 60 connections uses less power than a couple of mGig PoE switches.

In reply to a post by Pheasant:

I've seen various organisations attempt fibre to the desk over the years, and it never succeeds.

I've seen it used, 20+ yeras ago at 10 Mbps ... it was insane, the cards for the PCs and adaptors for printers blew the budget. It worked though...

Yep. When I say it never succeeds, I meant from a commercially sustainable approach.

Edit: Just be clear before the nitpickers kick into gear 😅- by this I mean mass rollout of fibre to the desktop in a general commercial office setting - so not HPC, or other relatively obscure setups like high-end film production, graphics or post processing. There are some viable use cases.

Edited by Pheasant (Sat 21-Dec-24 09:33:41)

In reply to a post by Pheasant:

Yep. When I say it never succeeds, I meant from a commercially sustainable approach.

It was cost (due to how rare the cards were) that killed the project. They moved eventually to "fibre to the room" and a local distribution on copper. Switches, even back then, were the right place to do fibre.

In reply to a post by jchamier:

In reply to a post by Pheasant:

Yep. When I say it never succeeds, I meant from a commercially sustainable approach.

It was cost (due to how rare the cards were) that killed the project. They moved eventually to "fibre to the room" and a local distribution on copper. Switches, even back then, were the right place to do fibre.

Cards, transceivers/pluggables are a ton cheaper now, but copper will still be king on the desktop. Fibre still is not practical enough in a lot of cases in the 'user work area'.

A lot of organisations that operate in an open plan hoteling / hot-desking model as you say have done away with physical cabling in a lot of cases. Voice is now mobile or IP so you don't need a trad style PBX/keypad phone either, again less / zero data cabling. f you really want to save money that's how to do it.

In reply to a post by Pheasant:

In reply to a post by jchamier:

In reply to a post by Pheasant:

Yep. When I say it never succeeds, I meant from a commercially sustainable approach.

It was cost (due to how rare the cards were) that killed the project. They moved eventually to "fibre to the room" and a local distribution on copper. Switches, even back then, were the right place to do fibre.

Cards, transceivers/pluggables are a ton cheaper now, but copper will still be king on the desktop. Fibre still is not practical enough in a lot of cases in the 'user work area'.

Even at the current cheaper prices, copper still at 10gb beats fibre for price. Also for am4/5 and intel mainstream sockets fibre or dual fibre cards is a nightmare.

Try dual graphics cards and a sfp card in a am4/5 mobo and then cry........

Putting aside the central or switch end for a moment, and just considering the client end…

Still have to at least get an adapter or card to accept a ONT pluggable. That or equip every workstation with a discrete ONT with a copper interface. That might be another £10 to £50 per device, but they need powering and stowing somewhere. The costs and complexity quickly spiral.

PON is not practical as a LAN tech, despite some savings on the cabling and on ‘switch’ ports it quickly gets eaten up elsewhere.

In reply to a post by Pheasant:

Putting aside the central or switch end for a moment, and just considering the client end…

Still have to at least get an adapter or card to accept a ONT pluggable. That or equip every workstation with a discrete ONT with a copper interface. That might be another £10 to £50 per device, but they need powering and stowing somewhere. The costs and complexity quickly spiral.

PON is not practical as a LAN tech, despite some savings on the cabling and on ‘switch’ ports it quickly gets eaten up elsewhere.

given the inbuilt and fixed contention, it would be a pointless idea for high speed desktop applications.

50 or 100XGSPON might be interesting, but I concur.

In reply to a post by Eeeps:

Does this exist - the use of PON technology in the office or home?

Seems like it is ideally suited to the office with many workstations.

PON is all about aggregating multiple users into a single uplink fibre, which dramatically reduces the number of backbone fibres to be carried over a long distance to the exchange, and the number of active ports needed to drive those users (reducing space and power requirements). Those concerns don't really apply to office environments.

If you did want to connect (say) 30 desktops with fibre, you wouldn't use PON. You'd simply run 30 fibre pairs(*) to each desktop, and bring them back to a 48-port fibre switch. You'd then be running ethernet directly over the fibre. All ports could be active simultaneously, carrying different traffic: there's no time-sharing of the fibre as there is with PON.

Now, let's suppose you did decide to deploy PON in an office environment. How would this be different?

- You'd still have to bring those 30 fibres back to one point, but that point would be a passive splitter rather than an active switch
- You'd need a one-port OLT to plug this into, instead of the 48-port fibre switch
- The client devices would either need an ethernet connection into an external ONT, or an SFP port carrying a GPON SFP module. But it would be simpler and cheaper just to use a low cost 1G or 10G ethernet SFP(+) module.
- all the users would be sharing the same up and down bandwidth. You'd get a much higher aggregate bandwidth by giving each user their own full-duplex ethernet connection, even at 1G.

So in short: regular ethernet (over either copper or fibre) performs better and is easier for clients to connect to. Mini OLTs with a few ports do exist, but the market for them is not offices, it's small WAN deployments.

Finally: for 1G or 10G links, most people would just use copper, since the switches and adapters are cheap. If the connections are more than 90m then you'd place extra switches closer to the users (and uplink the switches using fibre). Fibre to desktop only really makes sense if you need to provide speeds of 40G or more - and you would pay handsomely for the privilege.

(*) Single fibre strands could be used, with BiDirectional SFP modules. However, BiDi modules are more expensive, whilst the fibre cables themselves are cheap. If I were wiring fibre to each desktop, I'd run a 6-12 strand cable to each location for future-proofing.

Indeed. If it was a goer at all for LAN it would’ve been done by now.

Good old GPON has been kicking around since before the millennium. Matured like a good cheese or wine 🍷