In reply to a post by RobertoS:

There isn't an FTTC network. Fibre between a cabinet and its headend exchange, that's all.

There likely *is* a network for providing FTTC, because it is also the nascent FTTP network too.

Today, fibre to 80 cabinets in an exchange can be thought of as 80 individual point-to-point routes. Tomorrow, when it is 25,000 premises on FTTP GPON's, there will be so much fibre that it needs to be ordered well, and that only happens by being ordered well from the start.

So today, we shouldn't see aggregation nodes as the end-points of a point-to-point star network. We need to see them as the junction points in a linear fibre spine, or a tree-branch structure for the future.

In reply to a post by WWWombat:

So today, we shouldn't see aggregation nodes as the end-points of a point-to-point star network. We need to see them as the junction points in a linear fibre spine, or a tree-branch structure for the future.

On this point, there is something I can reference from BT...

In an old post to this forum, I showed a research paper from BT on "light grids", which talked about the possibility of joining exchanges, and dual-parenting cabinets for redundancy.

The diagram on page 10 shows a fibre spine in such a setup, with a sequence of 8 "remote flexibility points" that allow joints to FTTC cabinets, splitters, and spurs.

Given that a joint at such a point is likely to require a splice, it isn't hard to picture a "remote flexibility point" as an aggregation node complete with splice trays.

I have no idea whether BT are implementing this kind of proposal, but it isn't hard to see how the same kind of spine can be used in the paths out from an exchange, even when they are single-ended.

And to bring this back on-topic...

With such a distribution architecture in place, with plenty of spare capacity in the spine in the form of dark fibre, it is certainly possible for a "leased line" business to be built on top of this distribution, where fibre only needs to be pulled back to the nearest aggregation node, and spliced into a point-to-point circuit rather than a shared GPON.

These fibres would probably need managing separately back at the OLT/Handover node, to ensure lack of contention.

Both good posts, but neither of them relevant to the current position. There is no FTTC network.

The potential for one is a different matter, as is FTTC's possible updating to FTTP. I forget the current FTTC capacity provision back to the exchange, but assume it would be relatively easy to upgrade that or the aggregation point capacities.

Come the dawn of ubiquitous FTTP, even then I would expect CPs to feed into their own backhaul at headend exchanges. So no "Openreach network".

It is possible to argue that every ISP currently has an FTTC network, but that would be rather stretching the definition.

UPDATE:
2 visits by fibre engineers to establish the fibres don't quite reach the node (so that's 5 in total)
6th visit gets fibre connected to a different node that goes off to a different exchange. I tell BT that wasn't agreed and circumvents our resiliency (BT running out of south side of building to Watford and VM running north out of building to their switch box).

Absolute shambles.

I didn't see any mention of asking for resiliency in your original post - did you?

In reply to a post by Gadget:

I didn't see any mention of asking for resiliency in your original post - did you?

No I didn't mention it here because it's not part of the original BT problem.

From my experience BT's planning when it comes to leased lines is terrible! If they make mistakes in the initial planning process they do not try to expedite the order to make up for delays, BT have too many systems and procedures that hold up their work.
Virgin Media Business on the other hand always come across more personal and can expedite orders if necessary, but obviously at a cost if they are not at fault.

In reply to a post by vit0:

From my experience BT's planning when it comes to leased lines is terrible! If they make mistakes in the initial planning process they do not try to expedite the order to make up for delays, BT have too many systems and procedures that hold up their work.

Sounds exactly like their planning/ordering process for telephone/broadband, only with more rope to hang themselves (or the customer) with.