A question wrt ONT/PON

[#1]

Now this may all have been discussed long ago here and elsewhere, so apologies for perhaps being a bit late to the matter.

Following my recent conversion to fibre my curiosity was aroused (Oh dear! This can lead to issues on here...) and led me to look into the workings of the PON (Passive Optical Network) and the ONT (Optical Network Terminal) etc. To at least get a general, if superficial, understanding of how it works. Interesting! If ultimately rather technically complicated.

Looking at technical documents led me to a particularly 'interesting' aspect. One of the described functions of an ONT (or ONU in IEEE terminology) was to multiplex between different types of service. Cable TV, IP(Internet) and Telephone were the three mentioned in the literature. Implying a separate output socket for each service.

My recently installed ONT is small and neat and has three sockets: Power, Optical Input, Ethernet Output.

This old BT/Openreach document on ONTs shows several different types, none of which exactly match mine. Some have multiple Ethernet sockets - and some have one of more Telephone sockets.

https://www.bt.com/help/broadband/whats-an-openreach-modem-ont

When I originally heard of the transfer to a digital network this is how I originally assumed it was going to be. Plug your router into the ONT Ethernet port and your DECT phone into a BT phone socket on the ONT - surely the easiest and neatest all round technical solution?

But we seem to have ended up somewhere else. Why?

Was this a purely technical decision? A commercial/'political' decision? Or a purely cost/commercial based decision by BT? We know BT customers will just be able to carry on as normal - after plugging their DECT phones into the BT router - with the router doing the multiplexing rather than the ONT. But I understand BT's 'Digital Voice' is a closed proprietary system, rather than an open system. Did BT decide to go this way with the ONT (IP only) purely to keep their existing (mostly non technical) landline telephone subscribers captive? On the basis: "If the [-Censored-] have already deserted us why should we cater for them?". If so, I am surprised in today's world such a decision would be allowed politically. Then again we have (or had) 'locked' mobile phones.

Does anyone have a quick answer?

TIA

[#2]

The document you reference is old - and does not describe the ONT currently installed in domestic (home) installations. See attached picture for the current hardware, or something very close to it.These merely convert the signal from 'light' to one which your router can understand - digital. Any peripherals (phone, TV, desktop/laptop w.h.y.) run off the router, either via Ethernet (cable), or wireless.

[#3]

...I know that.

The question is: "Why?"

[#4]

My understanding is the Telephone socket incorporated into the ONT was just a ATA adapter, so would only support a standard analogue phone handset.

Some routers now incorporate both a ATA and Digital Base Station for DECT device. 

EDIT: Maybe consider using AI to gain an answer

[#5]

'Why' what? That is the technology designed to provide FTTP.

[#6]

"Following my recent conversion to fibre my curiosity was aroused (Oh dear! This can lead to issues on here...) " 😓

John, please read my question. Please answer MY question as posted - that's the question I want the answer to, not another question of your own devising. If you don't have an answer to MY question, fair enough. No problem

Thank you.

[#7]

You referred me here from my query elsewhere.

As far as I can see the BT full fibre VOIP has the oprtion of plugging the phone into the router - PLUS you can have (free) additional phone adapters which plug into a mains socket.

Just spotted you should take medical advice before using these if you have  a Pacemaker!!!

It looks like EE also do phone adaptors - at £19.99 each. WOT a bargain!

Maybe BT's Digital Voice concept is so proprietary that even ee don't have it?

[#8]

@pvmb 

Because Openreach are only contracted to supply the property with a data connection. The ONT is the termination of their extent of supply.

Other services such as Internet access and VoIP that use the data connection, is the responsibility of others. In a past life when the GPO was the only supplier of a telephone service, Openreach was not a separate company and the market had not been opened up, things were contractually much simpler.

[#9]

"Maybe BT's Digital Voice concept is so proprietary that even ee don't have it?"

Could be! I've no idea. But this seems to be the issue - complexity. Whereas the 'obvious', simple solution was not the route taken. I am simply curious to know why not. The exact reasons why we are where we are.

(I reckon this has all been asked and answered somewhere in the past, but am unfamiliar with when and where.)

[#10]

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@Baldrick1 wrote:

@pvmb 

Because Openreach are only contracted to supply the property with a data connection. The ONT is the termination of their extent of supply.

Other services such as Internet access and VoIP that use the data connection, is the responsibility of others. In a past life when the GPO was the only supplier of a telephone service, Openreach was not a separate company and the market had not been opened up, things were contractually much simpler.

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Yes, but Openreach was also responsible for the landlines - before digital came along. So why were they not held responsible for continuing to supply technology for phones - via the ONT, rather than the existing NTE - regardless of who was going to supply the telephone service? (Commercial competition issues?)

[#11]

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@Baldrick1 wrote:

Other services such as Internet access and VoIP that use the data connection, is the responsibility of others. In a past life when the GPO was the only supplier of a telephone service, Openreach was not a separate company and the market had not been opened up, things were contractually much simpler.

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Yep, you'd still be told 'we'll connect you in 12-15 weeks, if we can be bothered, and you have no say in anything'.

[#12]

BT's DV was a closed system, only BT offered it. I believe no other isp wanted to use it and offered their own solution instead. Instead of allowing the device to be configured by the user, OR dropped it and sought, only 1gb 1port and 2.5gbit 1port devices along with the multiport 4 port ones.

in the long run its better this way

[#13]

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@Dan_the_Van wrote:

My understanding is the Telephone socket incorporated into the ONT was just a ATA adapter, so would only support a standard analogue phone handset.

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Suggesting that, originally, the thinking was different? Then again, for very vulnerable customers (with personal alarms) these might still be in use.

It seems to me possibly to come down to two broad 'explanations':

1. Disreputable or 'conspiracy' type (which is not my style) purely commercial/competitive explanations.
2. Overall cost considerations (which presumably did have political input).

The costs to BT of conversion to a diginal network (ultimately every premise in the UK) must be enormous - I don't know how it is shared out. They must have pointed this out to politicians and said the simplest and fastest, and lowest cost, approach for us is to implement a single service type (IP) at the customer premises.

[#14]

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@pvmb wrote:

Yes, but Openreach was also responsible for the landlines - before digital came along. So why were they not held responsible for continuing to supply technology for phones - via the ONT, rather than the existing NTE - regardless of who was going to supply the telephone service? (Commercial competition issues?)

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 My understanding is that after the break up, BT Wholesale were responsible for providing the copper landline, Openreach responsible for stitching a data connection onto the copper landline and BT Retail et al for providing a phone and Internet service.

[#15]

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@pvmb wrote:

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@Dan_the_Van wrote:

My understanding is the Telephone socket incorporated into the ONT was just a ATA adapter, so would only support a standard analogue phone handset.

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Suggesting that, originally, the thinking was different? Then again, for very vulnerable customers (with personal alarms) these might still be in use.

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vulnerable customers are the isp's issue not OR, remember that OR and BT are seperate companies 

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@pvmb wrote:

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1. Disreputable or 'conspiracy' type (which is not my style) purely commercial/competitive explanations.
2. Overall cost considerations (which presumably did have political input).

The costs to BT of conversion to a diginal network (ultimately every premise in the UK) must be enormous - I don't know how it is shared out. They must have pointed this out to politicians and said the simplest and fastest, and lowest cost, approach for us is to implement a single service type (IP) at the customer premises.

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Going to a distrubution point, greatly reduces that cost then to go to every premise in the uk. Also the existing equipment wat the exchanges for the final loop had become out of date and expensive to run. fibre allows 5x less exchanges, thats 5x at least operating costs for the exchange budget.