An aggregation node has nothing to do with leased lines (WES/BES/EAD etc)

I think you either replied to the wrong person or you are confused, it's ok though it is morning!

Good morning people

His reply does appear to me to be a direct reply to your post, and I'm sure he knows what he's talking about

He's saying leased lines are separate from the FTTx fibre network.

He's saying leased lines are separate from the FTTx fibre network.

..... and he is right.

In reply to a post by Zarjaz:

He's saying leased lines are separate from the FTTx fibre network.

..... and he is right.

Still - I assume they use the same ducting so if they've blown fibre to a cab that's on the way to our village it should mean the ducts are clear that far. From talking to people in the village there was no sign of BT until the day before it went live. Just seemed to me that BT did nothing for over 110 days.

In reply to a post by Andrue:

In reply to a post by Zarjaz:

He's saying leased lines are separate from the FTTx fibre network.

..... and he is right.

Still - I assume they use the same ducting so if they've blown fibre to a cab that's on the way to our village it should mean the ducts are clear that far. From talking to people in the village there was no sign of BT until the day before it went live. Just seemed to me that BT did nothing for over 110 days.

Hehe. Just had a similar conversation with the FTTC Coordinator for my part of the world...

Me: "When will Cabinet 14 go live?"
BT: "We've had some blockages, we think we've found the last one which is now due to be unblocked for 9th December"
Me: "Great news, but, it doesn't look like you've done anything, and you've even enabled Cabinet 22 which lies beyond Cabinet 14... so it seems that all three blockages have been in the last 20 metres? seems strange to need four months work to fix that?"
BT: "Well the ducting lengths are very short, so you wouldn't have seen them doing anything"
Me: "Well, maybe Cabinet 22 is fed from another Exchange? Maybe that explains?"
BT: "No, Cabinet 14 is definitely fed from your exchange"

At which point I just gave up. Not relevent to my cabinet.

I don't understand the full specifics and what blowing "Fibre" actually means.

My questions are:

Is that fibre just one fibre strand or multiples?
Can one fibre strand feed more than one cabinet (ie if you add a splitter)?
Are the cabs/etc daisy chained?

(at this point i'll explain that it seems odd to me that they may not have some kind of backbone in place then take feeds off that fibre to each individual cabinet or premise for a leasedline).

How many fibres can one of the sub ducting stuff support?

However am aware at this point that just because there is FTTC, doesn't necessarily mean you have a free route for an additional cable from t'exchange.

Don't take my response as an answer as Im curious myself.

In reply to a post by sjdean:

I don't understand the full specifics and what blowing "Fibre" actually means.

Had you followed the links to the Emtelle web site I gave you in one of my previous replies to you and the suggestion to watch B4RN's YouTube videos in another of my previous replies to you, you might have been more enlightened.

The Emtelle site will tell you about their fibreflow system, which is what B4RN are using and what I understand Openreach are using (though Openreach likely have other suppliers of similar products as well). The B4RN videos include fibre blowing and fusion splicing.


There's two differences between the Openreach and B4RN networks.

B4RN are using direct burial techniques - mostly moleploughing or trenching. Openreach are installing their fibres in ductwork. The difference is in installing the tubing - the fibre blowing and remaining steps are similar.

B4RN are running a duplex fibre to each served property - in essence, they're installing a switched Gigabit network. Openreach are installing PON for the FTTx roll-out. However, the different topology does not change the underlying fibre blowing and fusion splicing techniques. Openreach use the sort of trays seen in the B4RN videos to hold and protect spliced joints.

In reply to a post by David_W:

In reply to a post by sjdean:

I don't understand the full specifics and what blowing "Fibre" actually means.

Had you followed the links to the Emtelle web site I gave you in one of my previous replies to you and the suggestion to watch B4RN's YouTube videos in another of my previous replies to you, you might have been more enlightened.

Sigh. It's so frustrating speaking to you, which is why I've ignored many of your posts.

You snip posts and pretend you have all the answers and act as if everyone is beneath you, and you once again, have not actually answered anything.

That site doesn't go into very many details, however yes, I've already figured out from other methods besides the Emtelle website, but just from the anecdotes and what could be described as more detailed photographs out there, that there is some sort of sub duct technology with fibre blown through.

What isn't clear is necessarily what capacity the sub duct is, how many fibres are blown through, and how the network is actually laid out.

How many "fibres" are needed for a cabinet? Does each cabinet need its own sub duct? If you have three cabinets in a line from the Exchange, is that one "fibre" per cab, one fibre "bundle" (one or more strands) per cab, or does the furthest cabs signals travel upstream then get combined with the second cab, then further upstream through some sort of splitter or "aggregation"?

If they need to add capacity to a cab, presume more "fibres" are needed?

In reply to a post by David_W:

The Emtelle site will tell you about their fibreflow system, which is what B4RN are using and what I understand Openreach are using (though Openreach likely have other suppliers of similar products as well). The B4RN videos include fibre blowing and fusion splicing.


There's two differences between the Openreach and B4RN networks.

B4RN are using direct burial techniques - mostly moleploughing or trenching. Openreach are installing their fibres in ductwork. The difference is in installing the tubing - the fibre blowing and remaining steps are similar.

B4RN are running a duplex fibre to each served property - in essence, they're installing a switched Gigabit network. Openreach are installing PON for the FTTx roll-out. However, the different topology does not change the underlying fibre blowing and fusion splicing techniques. Openreach use the sort of trays seen in the B4RN videos to hold and protect spliced joints.

You didn't link to the B4RN videos, but I've googled them. They look fascinating.... The whole issue of splicing and bullets and trays are particularly interesting.

But again, for FTTC, is that what BT are doing, do they splice each cabinet to the next one upstream and so on and so forth up to the Exchange?

And as I realise I hijacked a Leased Line query, bringing it back on topic, would BT utilise existing subducts and blow one or more fibres from the Exchange?

I would imagine BT have several fibre networks. The Wholesale core, the fibre to cabinet and the ethernet business. I wouldn't expect they mix and match the networks. I would expect the FTTC network has an exclusive fibre spine.

But the tubes are in ducts so expansion is easy so long as you have duct space.

Fibre tubes are tubes. They could be divided into several tubes per cable, they could be unibore. You can blow more than one fibre into a tube.

B4RN is interesting as they appear to be burying tubes straight into the ground rather than using ducting. This will be cheaper but could be a mistake as any expansion it's back to the spade, any farmer ploughing it up and it will mean far mmore lengthy repairs. I am not aware of any other serious player doing it this way.

There isn't an FTTC network. Fibre between a cabinet and its headend exchange, that's all. There it is handed over to the CPs and their own backhaul which also handles ADSL2+. In BT Wholesale's case that is the WBC network.