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[lewisp8]

I was on a cabinet about 2300M away and had speeds between 16-17Mbs, about a year later planning for a new AIO cabinet was submitted and was built maybe 8 months after, this cab is maybe less than 200M away. The AIO was built and was dormant for about 6 months then a lot of work happened and I was migrated on to the new cab. I seem to sync at the full 79.99 Mbs now all the time. Does this kind of network rearrangement happen often, also how does it work? Am I connected through 2 PCP’s the original and the new AIO or do they bring more pairs in from the exchange and route it to the new cab? Also how does it work from the ISP side? And is this considered rare? Additionally is this sort of thing usually done to aid with capacity on existing cabs or solely for speed?

[Black Sheep]

I was on a cabinet about 2300M away and had speeds between 16-17Mbs, about a year later planning for a new AIO cabinet was submitted and was built maybe 8 months after, this cab is maybe less than 200M away. The AIO was built and was dormant for about 6 months then a lot of work happened and I was migrated on to the new cab. I seem to sync at the full 79.99 Mbs now all the time. Does this kind of network rearrangement happen often, also how does it work? Am I connected through 2 PCP’s the original and the new AIO or do they bring more pairs in from the exchange and route it to the new cab? Also how does it work from the ISP side? And is this considered rare? Additionally is this sort of thing usually done to aid with capacity on existing cabs or solely for speed?

This kind of scheme is called 're-parenting' and it's exactly as you say ..... the DSLAM (Fibre Cab) is basically brought nearer to the EU's vicinity.

To try and answer your questions ... with regard to my local area (other area's ARE available  ), this kind of scheme does indeed seem to be on the increase, but I don't have any hard figures to give you.

You WILL be connected through two Cabs but only in regard to your dial tone .... your broadband signal will only be generated from the 2nd, newer Cab.

The last question/s I can't help with I'm afraid ............. other than to say that two instances of this 're-parenting' on my local patch, were a result of pressure/signatures/etc from the local Parish council. I only found this out when working in the premises of the bloke who was the 'driver' for the campaign.

  

[j0hn]

What you describe is commonly referred to as an infill cabinet.
They choose a point in the D-Side (Distribution side, between you and the PCP) and place another cabinet. Sometimes it's a PCP and Fibre cabinet, in your case it's an AIO (PCP + DSLAM All In One).
This has the result of shortening the D-Side and increasing FTTC speeds for all those connected to the new cabinet.
It is usually BDUK that fund infill cabinets, though not exclusively.

If there are active FTTC customers on the original further away PCP being moved on to the new cabinet then there needs to be what is called a live-to-live migration.
Openreach need to contact and cooperate with every ISP who has a customer being moved. They need to arrange a date with the ISP's that the migrations will take place on.
It's a complicated and time consuming process which often runs into delays requiring the date to be rescheduled and delayed.
If a live-to-live migration is needed it usually adds months onto the time it takes to get these cabinets active. Until the live-to-live migration takes place no orders can be taken for the new cabinet.

There was a thread on TBB recently with a number of Openreach engineers disagreeing about the lines still being connected to the original PCP or not.

http://forums.thinkbroadband.com/fibre/f/4585565-cabinet-accepting-orders-but.html

Infill cabinets must have direct E side to the MDF so that they can be given an accurate Cabinet Assigned Loss (CAL) value. They cannot be routed as secondary cabinets.

Oh yes they can! Believe me, im a Openreach Engineer for a year now. The First PCP with the pressurised E side cables from the Exchnage is the Primary Connection Point, and the infill All-In-One cabinet that is situated further down the D side of the network (Grease filled cables) is the SCP, Secondary Connection Point.

Listen to what witchunt is saying ....... wink

What you are talking about is out of your hat.

Nobody is going to open up a mainside cable and fit a dozen airblocks and straps into the dside cables to physically bypass a cab.

They certainly cut away the original E sides to (I think) 14 in Caversham then turned what were 14/1 and 14/2 into ‘full’ cabs ......

I'll bet my best twisting cutters them pairs are still in the original cab.

If you are dropping an all in one cab on 3 dside cables that could be fed by 3 different mainside cables, you'll need 9 airblocked straps in the cab hole. That's assuming you can work on the mainside joints as a lot are too tied in with all the fibre tubes on top of them nowadays.

I've had to divert pairs off of the new all in one cabs and put them back on the original (don't ask why! ) and did have to fit a strap, but in the AIO cab hole! The pairs were in the original cab just like they always were.

So if tapping through for spares in the original cab I might inadvertently be taking a spare E from one of the Frankenstein cabs further on ?

In the example I was on about these weren’t AIO cabs, these were fibre twins added to the original SCP’s, and these SCP’s bastardised to become PCP’s.

Seen both SCP’s be turned into PCP’s (fed from existing PCP’s) and shown as a MDF>PCP1>PCP2>DP (where PCP was the old SCP). Also seen where an AIO was dropped after a PCP so MDF>PCP1>PCP2 (new AIO) > DP. Obviously the required live to live migration takes place after it is installed and commissioned to stop any cross talk from multiple DSLAM’s that have live circuits being moved into the new PCP2.

Your correct taking any spare E side in say PCP1 maybe a spare for PCP2 as well but as you know when they’re no useable spares PTO is called to tap out some clean pairs. The E sides between PCP1 and PCP2 are also classed as E sides but will be PET cable.

A man who is on my wavelength! Never known a D side from a PCP be ripped out when fitting a AIO further down the D side, and replaced with a pressurised E side cable bypassing the other PCP. Would mean running new cable all the way from to the MDF to the AIO and BT wont invest that money even back in the days when BT invested in copper!

Sometimes they have to if the new AIO is fed by two gaining cabinets that’s policy to remove pairs from the first cabinet and joint straight through st the base of the PCP. Most of the time it’s only fed by one cabinet so no problem to put an AIO further in the network.

I'm none the wiser.

edit: a little more...

There are also EO (exchange only lines) network rearrangements, which often use AIO cabinets too.
Instead of picking a point in the D-Side (there isn't 1) they pick a point in the E-Side and site a cabinet. Sometimes they place the cabinet right outide the exchange.
Some EO line rearrangements will be routed to an already existing nearby PCP.
These are commonly referred to as network rearragements. They can be extremely expensive so again are usually BDUK funded projects.

Sometimes infill cabinets also have EO lines routed to them at the same time.
If in any scenario any FTTC subscribers are moving cabinet then a live-to-live migration is needed

[gt94sss2]

In January 2016, Openreach said they had plans for upto 2,800 network rearrangements (to install new FTTC cabinets) between then and 2020/21

[Black Sheep]

There was a thread on TBB recently with a number of Openreach engineers disagreeing about the lines still being connected to the original PCP or not.

IF the task at hand is a 're-parenting cab' ......... then take it from me 100% there will be NO E-side cable in the new cab, and as such the dial tone will still be routed through the original cab.

You are perfectly correct in your comment j0hn ....... we simply 'drop' the new (AIO) cab on the D-side cable. That is it, nothing else required with regard to Openreach cabling, there's obviously more work involved around the powering of the cab, etc.

Feel free to re-post this on TBB site if you think it may help the thread. You could add I've been an employee for well over 30yrs now, if longevity carries any clout over there  ?? (don't want to give the exact for privacy reasons).   

[Icaraa]

Agree with Black Sheep. Another long term employee here.

All of the new AIO infill cabs that have gone in are effectively plonked on the existing D-side network. The pairs do go through the old cabinet and remain. A new jointbox sits near the AIO cab usually over the D-side cables we want to intercept. Then some new cables are run from there to the AIO cab and come up as E and D-sides in that new cab.

Indeed, on any subsequent job for those lines the routing shows both cabinets.

So the cables from original PCP  to infill PCP are NOT pressurised. I would argue that doesn’t really matter these days. Chances are most customers will move to FTTC in areas where infill cabs exist as speed must be slow, and how many people actually use their landline phones now anyway?

[burakkucat]

A query from the curious . . .

When I have had the opportunity to see the contents of a joint-box associated with a PCP, there appears to be a joint allowing a different type of cable to be the E-side tail from the PCP. In the case where an AIO has been sited "on top" of a group of existing D-side cables, is a strap made between the E- & D-sides, in the joint box at the existing PCP?

I guess my query could be reduced down to the question "Could an operative of Kelly Communications or M.J.Quinn cause problems (for customers whose circuits are now via the AIO) by inappropiate manipulation of jumpers within the existing PCP?" 

[Black Sheep]

A query from the curious . . .

When I have had the opportunity to see the contents of a joint-box associated with a PCP, there appears to be a joint allowing a different type of cable to be the E-side tail from the PCP. In the case where an AIO has been sited "on top" of a group of existing D-side cables, is a strap made between the E- & D-sides, in the joint box at the existing PCP?

I guess my query could be reduced down to the question "Could an operative of Kelly Communications or M.J.Quinn cause problems (for customers whose circuits are now via the AIO) by inappropiate manipulation of jumpers within the existing PCP?" 

Hmmm ?? I'm not 100% certain what is meant by the first paragraph, I'm afraid Mr Cat, but to answer the 'reduced version' ..... absolutely they could.

To try to attempt an answer to the first paragraph .......... there is no strap made in the underground 'cab box' of the existing PCP, when an AIO is fit further down the D-side cable towards the EU.

All that is required to give DSL service to the EU from the newly sited AIO, is, (In the existing PCP) re-jumper the dial tone from the E-side cable to the D-side cable just as we would if the EU had ordered a bog-standard PSTN circuit.
Then, we head off to the new AIO Cab and jumper the PSTN signal through the allocated DSLAM ports, and back out on the D-side cable towards the EU.

In a nutshell ...... the work required is exactly the same as if the EU was fed from a normal PCP with a normal sister DSLAM cab, but with the additional work of removing the old DSLAM tie-pairs in the existing PCP.

Does this make sense at all ??

# As with all things in life, there may well be an anomaly whereby a particular AIO had had new E-side cabling provided to it ?? I have yet to see such a beast .... and tbh, doubt I ever will. 

[burakkucat]

You have fully answered my query, thank you. 

[lewisp8]

Thanks for the responses! Very interesting regarding how these are setup. I would have thought in this day and age that it’d be be easier to use the fiber to supply the landline side of things via some VOIP interface in the new cab? Then you could remove all of the E side before the AIO infil and just keep the D side from the infil cab to the EU? I suppose this might provide some problems to users on legacy DSL products. Additionally has anybody seen a G.Fast pod attached to an AIO, is it even possible?

[licquorice]

But why spend money putting extra technology in the cab when there is a perfectly good copper cable already providing the functionality.

[gt94sss2]

I would have thought in this day and age that it’d be be easier to use the fiber to supply the landline side of things via some VOIP interface in the new cab? Then you could remove all of the E side before the AIO infil and just keep the D side from the infil cab to the EU? I suppose this might provide some problems to users on legacy DSL products.

As you suspect, the LLU ADSL operators in particular would not be happy if they removed the E side copper. Having said that, BT is supposed to switch its network to VOIP in a few years..

[licquorice]

Hmm, wasn't that supposed to have happened about 10 years ago. 

[kitz]

Yup it was in the original plans for 21CN for a full IP network.   I believe a couple of exchanges did go live.     Don't know what happened, but in ~2007 they pulled their plans and I was asked to remove any info about which exchanges were.

My checker still bears the scars of what was supposed to happen, but never did.