In reply to a post by WWWombat:

The splitter device takes in the one E-side fibre, and spits out 32 D-side tails. There is space for 4 of these devices in a node, but the node only comes with one pre-installed.

IIRC, that device appears in the photo as a fatter tray at the top of one side, with none at all on the other side.

When the node is first deployed, one D-side fibre is spliced to the device. The other 3 fibres (plus spares) will be stored in the top-most of the slimmer trays, and the 3 slots for the other devices will be empty.

When more capacity is needed, I guess they add an extra splitter device, splice it to a new D-side fibre, and put the 32 tails into the red trays.

Ah, ok.
That makes sense, I think we have 3 DP's (including ours) connected to the Splitter Node, I say think due to our DP is the only one at the moment that can order FTTP, might also be down to my local MP writting a letter to Gavin Patterson (CEO of BT Group plc) about our hardware.

So in theory we would then have a possible of 10 or 11 to 32 fibres at our DP, But its probably 10 or 11, I know the FTTP Engineer said there was loads of fibres at our DP, or would they say that for 10 fibres.

I know there is about 21 homes connected to our phone pole and some have more than one phone line, but lets assume one FTTP per home, so we would need to have 21 fibres at our DP for us all to get FTTP.

As far as I know at least 5 have open orders including ours, I say open due to we are waiting for Openreach to fix their blunder with the trays at the splitter node.

So if we go with say 10 to 11 fibres at our DP we are already half way populated

Paul

I think the number of fibres is likely to be a multiple of 12 - the cables are constructed with the fibres bound together in groups of 12, and are best split apart in that grouping.

They might then dimension that as 10 useable, and 2 spare for breakage.

In reply to a post by WWWombat:

I think the number of fibres is likely to be a multiple of 12 - the cables are constructed with the fibres bound together in groups of 12, and are best split apart in that grouping.

They might then dimension that as 10 useable, and 2 spare for breakage.

Yeah, very possibly, I will find out when I see them come back to finally get to start our first visit.

Paul

The splitter isn't the limitation, it is the optics back at the head-end exchange.

Current generation used GPON optics, which gives 2.5Gbps down, 1Gbps up.
Next generation 10GPON gives 10Gbps down, 2.5Gbps up.

In reply to a post by WWWombat:

The splitter isn't the limitation, it is the optics back at the head-end exchange.

Current generation used GPON optics, which gives 2.5Gbps down, 1Gbps up.
Next generation 10GPON gives 10Gbps down, 2.5Gbps up.

I was referring to asking the engineer about the fibres, not the splitter.

Sooo, 2.5Gbps down per fibre going into the splitter, so if everyone hammered their connection at the very same time we would get a download speed of about 78.125Mbps, haven't we discussed this in another post.

No chance in abusing the upstream (1Gbps / 32 = 31.25Mbps) LOL.

I rather like the 10Gbps shared by 32 lines LOL.

*** update ***
Also with our fibre cable, back in July 2015 they replaced it with a 96 fibre core cable so that would be 8 lots of 12 fibres.

Paul

Edited by PaulKirby (Fri 19-Aug-16 19:16:24)

Ahh ok, for some reason I thought it was down to splitter capability.

Is it possible to have multiple head-end feeds going in to a single splitter to reduce contention?

KCOM are using GPON, and even the Openreach FTTP ONT, but are very generous with the speeds, particularly on the business packages. Ranging from 250/125 to 1000/500.

Edited by deleted (Fri 19-Aug-16 20:23:31)

In reply to a post by PaulKirby:

Sooo, 2.5Gbps down per fibre going into the splitter, so if everyone hammered their connection at the very same time we would get a download speed of about 78.125Mbps, haven't we discussed this in another post.

Ironic that it comes up to being about the same capability as an FTTC line

Seriously, though, they can use statistical stuff to determine a reasonable maximum to the headline rate while not triggering too much congestion. The cable industry has had to work like this for years...

IIRC, the cable guys figure they can sell a top-tier headline speed where 4 such subscribers could fill things up. If BT chose to work to similar targets, you'd be looking at top packages of 600Mbps.

In reply to a post by adriandaz:

Is it possible to have multiple head-end feeds going in to a single splitter to reduce contention?

Nearly. The splitters are often described as 2x32, meaning two incoming feeds, and 32 subscriber feeds.

However, I think the head-end feeds are really meant to allow for dual-parenting for reliability/availability reasons, rather than for capacity reasons. I'm no expert on optics, but I suspect that load-sharing would require multiple wavelengths, and the ONT's likely don't have that kind of capability at all - never mind the ability to alter dynamically.

On that front, though, I believe you can run both GPON and 10GPON through the same splitter at the same time, even from a single head-end, because they do use separate wavelengths. The ONT used by the customer then determines which service he is on.