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An somewhat intriguing question - perhaps for BT Group / Openreach folks in the know  - a recent update on a thread here suggests that in early / original ECI-based OLT exchange areas (I think blown rather than connectorised deployment) have been later in-filled with (in this case) a Huawei based OLT at the same exchange.
Is this normal practise in the original ECI handover exchange areas?
The post in that thread mentioned two neighbouring properties one served on ECI and the neighbour served on Huawei from the Chester South exchange area.
TIA
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Almost every exchange (or straight up all of them) with an ECI OLT has a Huawei or Nokia OLT. Often multiple of.
If the exchange has a Huawei cabinet anywhere in it then it has a Huawei OLT.
Seeing as almost all BDUK cabinets are Huawei and they stopped installing ECI cabinets in mid 2016 that means there's next to no exchanges with only ECI cabinets.
My exchange has 1 ECI OLT, at least 1 Huawei OLT (though I believe 2) and a shiny new Nokia OLT.
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So fair to say that in the case of the OP in the Zen thread, that later FTTP in-fill would have been constructed using a completely separate PON infrastructure to the original PONs for the ECI deployment.
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So fair to say that in the case of the OP in the Zen thread, that later FTTP in-fill would have been constructed using a completely separate PON infrastructure to the original PONs for the ECI deployment.
That's a certainty. There's no new ECI FTTP PON's being deployed.
However if your local PON is ECI and you haven't yet ordered FTTP and capacity exists on that PON... bad news for you.
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Yep. Somewhat interesting original design planning / capacity planning considerations from Openreach when if there was no FTTC available to these properties and FTTP was the only way forward, that they did not include enough local capacity for all properties when they completed the initial ECI-based rollout. Perhaps there is more to it historically in that particular case. New development / new properties that didn't exist then? Odd
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My exchange has 1 ECI OLT, at least 1 Huawei OLT (though I believe 2) and a shiny new Nokia OLT.
If you said Adtran OLT then that would be interesting
[C'mon Openreach don't be shy, there must be some somewhere outside the pilot / trial exchanges]
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The ECI OLTs have no switching fabric so all the GPON ports on the card are backhauled by gigabit ports on the same card. Each CP needed a Cablelink to each line card.
Some interesting decisions were made for sure.
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Sounds like a fabulous architecture. Not. 😂
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Is there something special about ECI that means the only experience the average UK consumer has with their products is wholly negative? Are things like G.INP not working on their FTTC cabinets and this weird OLT line card design just a result of being early into the market, or were they just procured badly?
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Quite. Imagine that Openreach have not been in a huge rush to upgrade from an ECI based PON
Even stepping them to XGS-PON could be sticky, doable, but not sure if those early PON designs were fitted with a WDM (like they fitted later) enabling another light source into the PON without disrupting / disconnecting existing customers. I suppose they could prep the change, and make a short one time disconnection to introduce a WDM onto the headend. Fortunate I suppose it’s only 50K or so customers on ECI based FTTP gear.
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The ECI OLTs have no switching fabric so all the GPON ports on the card are backhauled by gigabit ports on the same card. Each CP needed a Cablelink to each line card.
And how many PON ports on a linecard?
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jpm
They were very early in the market. I looked at their kit during an ITT in 2004. It was based on having a wavelength for BB and a Wavelength for TV distribution. Back then it was state of the art way ahead of any other supplier but with hindsight ( always very useful!) it was designed for situations that have not arisen in the UK. ( not allowed regulatory wise at the time ) .
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Dependant on generation of the HiFocus chassis - I think from a quick search they were GPLT4 line cards - 4 PON ports per line card.
Kitcat doubtless would be able to confirm.
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And you need a separate cablelink per line card, not per chassis?? Sheesh.
I can't think many ISPs would want to buy a 1G cablelink just to serve a handful of customers (although it's a theoretical maximum 128 on 4 PON ports)
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From what I can tell it looks like these early Hi-FOCuS MSAN chassis have two supervisor cards (what they call IPNI) each with 8 x SC uplink ports. The line cards have a dual ‘star’ connection back to each IPNI - rather than a non-blocking backbone switching matrix as is now commonplace. I would expect that any cablelinks are connected to the IPNI uplink ports.
Could be totally wrong though 🤣
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You have been busy with your research Detective crazy/tasty poultry guy 🤣
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🤣🤣…define ‘research’ Inspector; is it flicking between the newspaper, breakfast and phone on a sunny Saturday morning? Tasty poultry guy out 😎
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Pheasant
Racking my brain for the answer, I think you are correct with 4 PONs per line card, but the backhaul was no off the cards but of a different card with multiple Ge potentially. so Not 128 per Ge backhaul.
They were not originally designed for multiple operators to connect to ( Nowhere else in the world had that requirement as they were all vertically integrated operators) but to be able to aggregate across multiple Ge to the same end point. In 2004 no-one was considering needing more than a couple of Ge for BB and 10Ge ports were only used in the Core. The Supervisor cards also handled the 'TV' signals and were resilient. ( Total Internet bandwidth was only about 40Gb nationally) see https://www.thinkbroadband.com/news/1664-top-10-fast... for high speed internet in 2004!!
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Thank you Kitcat. This is what I found in an FCC archive! taken from an Hi-FOCuS 960E DSLAM doc. This might have been a generation later c.2007 tech!!
System overview
Front chassis, view of card arrangement
Supervisor cards (IPNI) had the uplinks, 8 x SC apparently. Internal connection was via 1G (but they also mention 10G?) links, so called ‘dual star’ from each line card back to each supervisor card. Non-blocking / switching fabric wasn’t a thing just yet in ECI land
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Pheasant
Recollections that the earliest variant was nicknamed the pizza box as it was that size and had a PON of 64 (feeding 1st and 2nd splitters of 8) with 1 pair of resilient Ge back to the Backhaul via a edge router. It wasn't really scalable.
Apart from at Ebbsfleet (Greenfield new town) BT was not allowed to rollout FTTP at that point as it would have prevented other ISPs from providing service by LLU. It took a number of years to get developments made so that regulatory approval was agreed (despite Sky and TalkTalks objections) and the present FTTP design rolled out.
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Recollections that the earliest variant was nicknamed the pizza box as it was that size and had a PON of 64 (feeding 1st and 2nd splitters of 8) with 1 pair of resilient Ge back to the Backhaul via a edge router. It wasn't really scalable.
That's the one I remembered. So the larger ones you could install fabric cards in them but that required more power, cooling and a backplane swap and apparently wasn't done so even on the bigger boxes it was, as mentioned, everything to the supervisors which in turn provided all the backhaul ports.
The gigabit line cards were for cabinets as I vaguely recall. A whole bunch of them scrunched into the backplane and back to a supervisor.
Either way I recalled OLTs with the capacity on the GPON-side badly overbooked between there and backhaul.
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