FTTP curiosity

[#1]

There was quite a bit of telco work in our area (north london) recently. Whilst openreach were involved, I don't believe the work was carried out entirely by them but may be wrong.

The end result is, what I believe are fiber terminal blocks installed at the top of the existing telegraph poles. These look to be the 12 terminal type.

Now, someone a few doors down (connected to the same pole as me) looks to be getting gigabit FTTP installed. I assumed their new line would run from their premises, to the fibre terminal block at the top of 'our' pole, and that would be it.

However, openreach have made a second overhead cable run between 'our' pole and the next one (40m or so down the road) which I believe is soley for this customer's connection. It's not clear if they are connected to the fiber TBC atop 'our' pole.

The engineer was a bit evasive IMO, but my takeaway from it was that the fiber equipment at the top of 'our' pole was not available to the party providing this customer's new FTTP connection. I had not realised this kind of sharing/segregation existed on Openreach's network, especially at the top of the poles.

What might cause the need to run a new overhead cable, but between poles?

[#2]

@keeka

The unit attached to the pole is probably a Connectorized Block Terminal (CBT). They come in varying sizes (4, 8, 12 at least). The CBT's are "daisy chained" along a circuit. OpenReach do share fibres back from a CBT to the Internet Head End (where it connects to the national network). Capacity wise I believe it's about 30 connections that can get shared.

If you want to check your property look at the following. You need WBC FTTP in the left hand column.

https://www.broadbandchecker.btwholesale.com/#/ADSL

Brian

[#3]

@bmc

What I don't get is, having provisioned the poles for FTTP, why they then sling a long overhead cable run from one pole to the next at the time of this customer's install. This presumably carries this one customer's connection.

This is in a built up residential area where, up until now, the only overhead connections were from premises to the nearest pole. Nothing between poles, it was all below ground and inspection covers.

[#4]

I suspect that it is a matter of capacity.  With copper, a pole to pole over head cabling would be thick and heavy as every circuit requires and individual copper pair.  With fibre multiple connections can be carried by a single fibre "cable".

Especially if existing ducts are blocked of full, pole to pole provision of fibre might be more practical / proficient / cost effective.

[#5]

@Townman

I see. So this is probably the first customer, connected to that particular pole, to sign up for FTTP. Subsequent ones will share the same 'cable'.

Still, it seems odd the TBC on this pole (if that is what it is) was not sufficient to hook this customer up to fibre. I could be wrong, and what I think is a fibre TBC is not. They are however on most all other poles in the street as I had a chance to see them up close when they were being fitted.

EDIT: just to add my asumption here is that any fibre TBC at the top of a pole is connected to the below ground cables via the conduit running down the pole.

[#6]

OK, it turns out our pole is the only one without a new fibre CBT. What I thought was, is in fact something else. All the other poles do however have one and it is 8 port, not 12 as I said earlier.

So this explains the need for the new inter-pole link.

Apologies for the time wasting post!

[#7]

@keeka 

Never time wasting if you seek knowledge.

This is an 8 port CBT for an underground chamber. Pole mounted ones are similar.

It is 5th or 6th (and last) on the "Daisy chain" for my street.

Brian

[#8]

@keeka 

There is other equipment deployed for FTTP connections. For example, individual ciruits will feed back to an Aggregation Point where heavy duty fibres then take it onwards.

If you'e interested you could post a picture of the top of the pole serving you and see if anyone can identify what's there.

Brian