On Sat, 08 Aug 2020 12:39:30 +0100, Scott wrote:

Returning to the original topic, I assume that most exchange only
lines will be underground. To replace them with fibre optic, would the
road typically require to be dug up for the entire route, or could
they be pulled through using the existing copper cables?

If ducted they can shove (literally) a duct for the fibre between
chambers. How you the get from the chamber to indivdiual premesis may
well require digging, Install all the fibre and progressively switch
over then recover the copper.

Direct buried copper would need digging out and duct laid for the
fibre or just abandoned and an amroured fibre cable ploughed in (if
such a thing exists).

Would selling the copper as scrap help to pay for the project?

Well it'll help I guess, if they can recover it easily. Ducted would
just pull, direct buried would need digging out. It might "cheese
wire" up through soft ground but I wouldn't like to bet on it not
just snapping.

--
Cheers
Dave.

On Sat, 8 Aug 2020 13:12:49 +0100, The Natural Philosopher wrote:

I suspect they are going to have a solution that works over 5+
miles of copper, is easy to install (swap out the rear half of
the
NTE?) and emulate analogue POTS.

its called fttp.
the cost of laying fibre is in the end less than the cost of
putting
in powered repeaters.

Powered repeaters? AIUI FTTP is provided over GPON it doesn't have
powered repeaters just passive optical splits that can be stuffed
into a hole in the ground miles from the head end.

That's exactly why I said what I said Dave.
The cost of fibre is less than the cost of powered repeaters (for
copper)

ADSL2+ will do the 500 kbps required for voice only provision over 3
or 4 miles of copper. Though I think ADSL goes out the window along
with the the PSTN. But the technology is there to provide such a link
over a simple copper pair.

It's also complicated by the Universal Service Obligation that is now
in place for broadband. You have a right to at least a 10 Mbps
service and Openreach or Kcom have to provide it. There are a few
gotchas like a cap on the construction costs.

Is there a fibre equivalent to 50 pair armoured cable that is
buried
direct? Miles of such cables feed many places around here, the
only
over head bits being from the road to premises. Trenching for a
duct
is very expensive, even ploughing in a duct isn't cheap. Fibre
doesn't like being stretched, not sure you could plough in an
armoured fibre cable.

Armoured fibre will take an enornous number of 'circuits' . So very
little fibre replaces a 50 pr. One fibre should do

But you need one fibre (at least, spares?) from where ever the
optical split is to each served premises. The optical split may only
have one, or more likely two fibres, feeding it from the OLT.

The 50 pair armoured direct buried cable feeding POTS to us also
feeds other places along it's route from beyond us and back to the
exchange. These places are well spaced apart, 1/4 mile or more.

You can get mutltiple tube ducting systems designed to distribute
from the split to premises. But again that would need to trenched or
ploughed in and chambers constructed to hold the duct splits to
replace the joint posts/bullets.

I am not sure BT has *ever* buried cables in the soil without ducts.

They have here...

The multiple 200 pair cables running down the village are ducted. And
they shoved a fibre duct through that ducting to get the fibre down
to the village's FTTC. That's the one that runs under our forecourt.

--
Cheers
Dave.

On Sat, 8 Aug 2020 13:14:31 +0100, The Natural Philosopher wrote:

I've yet to see anywhere with fibre popping out of the ground at
single
pole feeding a single premises with places spaced at 1/4 to 1/2
mile
intervals.

well if you had looked at my website that is precisely what you would
have seen.

My pole feeds me, and me alone, and the same for my nearest neighbour.

Who is how far away? And I assume from your other comment that the
underground parts are ducted as well.

--
Cheers
Dave.

On Saturday, 8 August 2020 16:01:10 UTC+1, Dave Liquorice wrote:


ADSL2+ will do the 500 kbps required for voice only provision over 3
or 4 miles of copper. Though I think ADSL goes out the window along
with the the PSTN. But the technology is there to provide such a link
over a simple copper pair.


Isn't that 500 kbps expressly what they will provide on a fibre connection when provisioning only for a basic connection? Not ADSL of any sort. A single voice connection wouldn't need that much bandwidth.

On 08/08/2020 16:03, Dave Liquorice wrote:
On Sat, 8 Aug 2020 13:14:31 +0100, The Natural Philosopher wrote:

I've yet to see anywhere with fibre popping out of the ground at
single
pole feeding a single premises with places spaced at 1/4 to 1/2
mile
intervals.

well if you had looked at my website that is precisely what you would
have seen.

My pole feeds me, and me alone, and the same for my nearest neighbour.

Who is how far away? And I assume from your other comment that the
underground parts are ducted as well.

yes
neighbour is abut 200 meters down the road, a manor house and a lodge.
each have their own pole


--
"If you dont read the news paper, you are un-informed. If you read the
news paper, you are mis-informed."

Mark Twain

On 08/08/2020 16:29, polygonum_on_google wrote:
On Saturday, 8 August 2020 16:01:10 UTC+1, Dave Liquorice wrote:


ADSL2+ will do the 500 kbps required for voice only provision over
3 or 4 miles of copper. Though I think ADSL goes out the window
along with the the PSTN. But the technology is there to provide
such a link over a simple copper pair.


Isn't that 500 kbps expressly what they will provide on a fibre
connection when provisioning only for a basic connection? Not ADSL of
any sort. A single voice connection wouldn't need that much
bandwidth.

64k



--
There is nothing a fleet of dispatchable nuclear power plants cannot do
that cannot be done worse and more expensively and with higher carbon
emissions and more adverse environmental impact by adding intermittent
renewable energy.

On 08/08/2020 12:07, charles wrote:
In article l.net,
Dave Liquorice wrote:
On Sat, 8 Aug 2020 11:28:19 +0100, The Natural Philosopher wrote:

I suspect they are going to have a solution that works over 5+
miles
of copper, is easy to install (swap out the rear half of the NTE?)
and emulate analogue POTS.

its called fttp.
the cost of laying fibre is in the end less than the cost of putting in
powered repeaters.

Powered repeaters? AIUI FTTP is provided over GPON it doesn't have
powered repeaters just passive optical splits that can be stuffed
into a hole in the ground miles from the head end.

Is there a fibre equivalent to 50 pair armoured cable that is buried
direct? Miles of such cables feed many places around here, the only
over head bits being from the road to premises. Trenching for a duct
is very expensive, even ploughing in a duct isn't cheap. Fibre
doesn't like being stretched, not sure you could plough in an
armoured fibre cable.

round heer, openReach have just been installing fibre on old fashioned
poles. I'm not sure of the reason.

That's how they did ours - just strung it along the existing poles along
with the copper.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Just had a look at Openreachs map of FTTP areas and according to that we are a couple of hundred metres outside a purple splodge showing FTTP in progress and in the 1/2 mile gap inbetween to a yellow splodge showing FTTP work to start in the next three months. Sods Law! I will bet it is 2025 at least before they bridge that gap.

Richard

Tricky Dicky wrote:

Just had a look at Openreachs map of FTTP areas and according to
that we are a couple of hundred metres outside a purple splodge
showing FTTP in progress and in the 1/2 mile gap inbetween to a
yellow splodge showing FTTP work to start in the next three months.

Are you currently on ADSL or VDSL?

Sods Law! I will bet it is 2025 at least before they bridge that
gap.

Are you currently on ADSL or VDSL?

We are FTTC, and were amongst the last in the locality to go to that.

Richard

Tricky Dicky wrote:

We are FTTC, and were amongst the last in the locality to go to that.

Wouldn't hold your breath for FTTP then (even 2025 sounds optimistic)
and protect your wallet if you investigate FTTPoD.

On 09/08/2020 11:45, Tricky Dicky wrote:
Just had a look at Openreachs map of FTTP areas and according to
that we are a couple of hundred metres outside a purple splodge
showing FTTP in progress and in the 1/2 mile gap inbetween to a
yellow splodge showing FTTP work to start in the next three months.
Sods Law! I will bet it is 2025 at least before they bridge that
gap.

We were in the "next group to be done" bit for 18 months or so, but then
it happened fairly quickly after that.



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Sunday, 9 August 2020 21:43:53 UTC+1, John Rumm wrote:
On 09/08/2020 11:45, Tricky Dicky wrote:
Just had a look at Openreachs map of FTTP areas and according to
that we are a couple of hundred metres outside a purple splodge
showing FTTP in progress and in the 1/2 mile gap inbetween to a
yellow splodge showing FTTP work to start in the next three months.
Sods Law! I will bet it is 2025 at least before they bridge that
gap.

We were in the "next group to be done" bit for 18 months or so, but then
it happened fairly quickly after that.



Whereas we were in the "wait for news ..." for the best part of two years. Then "if you haven't heard anything, it's not happening".

Took some emails to political people to trigger a change of view in Openreach.

Once decided, they were excellent. They came and installed the whole lot (more than 100 houses) with a team of people from across the whole UK. Very fast, friendly, considerate to everyone.

On Sat, 8 Aug 2020 20:21:19 +0100, The Natural Philosopher wrote:

ADSL2+ will do the 500 kbps required for voice only provision
over
3 or 4 miles of copper. Though I think ADSL goes out the window
along with the the PSTN. But the technology is there to provide
such a link over a simple copper pair.

Isn't that 500 kbps expressly what they will provide on a fibre
connection when provisioning only for a basic connection? Not ADSL
of
any sort. A single voice connection wouldn't need that much
bandwidth.

64k

For 1 channel of ISDN (which also goes out the window with the PSTN).
You had to have two channels with ISDN so 128 kbps plus 16 kbps for
signalling = 144 kbps.

As I say the technology exists for a pure data connection suitable
for "new POTS" to be provided over copper without any expensive
repeaters. Just change the rear plate of a current analogue NTE.

I can't see them managing to complete the "full fibre" network by
2025. The orginal target was 2033... The water has since become
middied by the goal posts being shifted to "gigabit capable" which
can include techonologies other than FTTP, like 5G.

--
Cheers
Dave.

On 10/08/2020 10:50, Dave Liquorice wrote:
For 1 channel of ISDN (which also goes out the window with the PSTN).
You had to have two channels with ISDN so 128 kbps plus 16 kbps for
signalling = 144 kb

technically, yes. Commercially, no. You could buy a single channel.

For more than two channels they tended to install a fibre that would do
2Mbps.

At one time this was a free installation, so many of our customers did
that, then cancelled their ISDN and ordered a leased line based on
pre-existant fibre...saving themselves several thousand installation.

God what we have now,we would have killed for back then.


--
Labour - a bunch of rich people convincing poor people to vote for rich
people by telling poor people that "other" rich people are the reason
they are poor.

Peter Thompson

On Sun, 9 Aug 2020 20:04:44 +0100, Andy Burns wrote:

Openreach map? Is that the Fibre First one or another?

We are FTTC, and were amongst the last in the locality to go to
that.

Wouldn't hold your breath for FTTP then (even 2025 sounds optimistic)
and protect your wallet if you investigate FTTPoD.

FTTPoD seems to have died, not surprising considering the prospective
install price, pricing structure and lack of ISPs offering service
over it it, with I think was limited to 300 Mbps. Over taken by the
"gigabit capable" system?

The DCMS Gigabit Voucher scheme (up to £1,500 per home, £3,500 per
SME) with broadband speeds less than 100 Mbps are elegible. Possibly
with a top-up from a regional development agaency, we have the
"Borderlands Inclusive Growth Deal" that doubles those amounts.
However the conditions for the Borderlands top-up would exclude most
people with access to FTTC as the "less than speed" is 30 Mbps.

Failing that there is Openreach's Community Fibre Partnership.

--
Cheers
Dave.

Dave Liquorice wrote:

I can't see them managing to complete the "full fibre" network by
2025.

Is that still the target timescale?

https://www.bbc.co.uk/news/technology-50042720

Why the hang-up with gigabit speeds?

https://researchbriefings.files.parliament.uk/documents/CBP-8392/CBP-8392.pdf

I have ~75 Mbps from a BT cabinet that I can *just* see if I lean out of
the window. Alternatively I could have up to 500 Mbps from virgin FTTP
where they have what is apparently called a "toby" in the footpath at
the end of my drive, same as this ...

https://www.chatteris.biz/blog/wp-content/uploads/2018/02/IMG_2286-Medium.jpg

Openreach map? Is that the Fibre First one or another?

This one Fibre First Cities, towards the bottom of the page.

Richard

On Sat, 08 Aug 2020 16:01:07 +0100 (BST), "Dave Liquorice"
wrote:

On Sat, 8 Aug 2020 13:12:49 +0100, The Natural Philosopher wrote:

I suspect they are going to have a solution that works over 5+
miles of copper, is easy to install (swap out the rear half of
the
NTE?) and emulate analogue POTS.

its called fttp.
the cost of laying fibre is in the end less than the cost of
putting
in powered repeaters.

Powered repeaters? AIUI FTTP is provided over GPON it doesn't have
powered repeaters just passive optical splits that can be stuffed
into a hole in the ground miles from the head end.

That's exactly why I said what I said Dave.
The cost of fibre is less than the cost of powered repeaters (for
copper)

ADSL2+ will do the 500 kbps required for voice only provision over 3
or 4 miles of copper. Though I think ADSL goes out the window along
with the the PSTN. But the technology is there to provide such a link
over a simple copper pair.

It's also complicated by the Universal Service Obligation that is now
in place for broadband. You have a right to at least a 10 Mbps
service and Openreach or Kcom have to provide it. There are a few
gotchas like a cap on the construction costs.

Just being silly now, but if Openreach claim the cost exceeds £3,400
can I offer to install it myself then put the job out to competitive
tender?

On 10/08/2020 11:19, Andy Burns wrote:
Dave Liquorice wrote:

I can't see them managing to complete the "full fibre" network by
2025.

Is that still the target timescale?

https://www.bbc.co.uk/news/technology-50042720

Why the hang-up with gigabit speeds?

https://researchbriefings.files.parliament.uk/documents/CBP-8392/CBP-8392.pdf


I have ~75 Mbps from a BT cabinet that I can *just* see if I lean out of
the window.Â* Alternatively I could have up to 500 Mbps from virgin FTTP
where they have what is apparently called a "toby" in the footpath at
the end of my drive, same as this ...

https://www.chatteris.biz/blog/wp-content/uploads/2018/02/IMG_2286-Medium.jpg


I have 26 Mbps from BT FTTC and have never used more than 10Giga in a
month.
What on earth DO people do with such massive speeds ?.

In article , Andrew
wrote:
On 10/08/2020 11:19, Andy Burns wrote:
Dave Liquorice wrote:

I can't see them managing to complete the "full fibre" network by 2025.

Is that still the target timescale?

https://www.bbc.co.uk/news/technology-50042720

Why the hang-up with gigabit speeds?

https://researchbriefings.files.parliament.uk/documents/CBP-8392/CBP-8392.pdf


I have ~75 Mbps from a BT cabinet that I can *just* see if I lean out
of the window. Alternatively I could have up to 500 Mbps from virgin
FTTP where they have what is apparently called a "toby" in the footpath
at the end of my drive, same as this ...

https://www.chatteris.biz/blog/wp-content/uploads/2018/02/IMG_2286-Medium.jpg


I have 26 Mbps from BT FTTC and have never used more than 10Giga in a
month. What on earth DO people do with such massive speeds ?.

my former neighbour put it quite well: "I have 3 teenage children"

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

On 10/08/2020 17:28, charles wrote:
In article , Andrew
wrote:
On 10/08/2020 11:19, Andy Burns wrote:
Dave Liquorice wrote:

I can't see them managing to complete the "full fibre" network by 2025.

Is that still the target timescale?

https://www.bbc.co.uk/news/technology-50042720

Why the hang-up with gigabit speeds?

https://researchbriefings.files.parliament.uk/documents/CBP-8392/CBP-8392.pdf


I have ~75 Mbps from a BT cabinet that I can *just* see if I lean out
of the window. Alternatively I could have up to 500 Mbps from virgin
FTTP where they have what is apparently called a "toby" in the footpath
at the end of my drive, same as this ...

https://www.chatteris.biz/blog/wp-content/uploads/2018/02/IMG_2286-Medium.jpg


I have 26 Mbps from BT FTTC and have never used more than 10Giga in a
month. What on earth DO people do with such massive speeds ?.

my former neighbour put it quite well: "I have 3 teenage children"

Another issue is online games. It takes longer to transfer a given
packet over a slower speed link. Gamers like snappy responses to their
input in order not to die online ;-)


--
€œThe fundamental cause of the trouble in the modern world today is that
the stupid are cocksure while the intelligent are full of doubt."

- Bertrand Russell

On Monday, 10 August 2020 17:30:29 UTC+1, charles wrote:
I have 26 Mbps from BT FTTC and have never used more than 10Giga in a
month. What on earth DO people do with such massive speeds ?.
my former neighbour put it quite well: "I have 3 teenage children"

One of my neighbours only has internet on her mobile phone.

Her husband and her have 5 children.

Owain

On 10/08/2020 17:33, The Natural Philosopher wrote:
On 10/08/2020 17:28, charles wrote:
In article , Andrew
wrote:
On 10/08/2020 11:19, Andy Burns wrote:
Dave Liquorice wrote:

I can't see them managing to complete the "full fibre" network by
2025.

Is that still the target timescale?

https://www.bbc.co.uk/news/technology-50042720

Why the hang-up with gigabit speeds?

https://researchbriefings.files.parliament.uk/documents/CBP-8392/CBP-8392.pdf



I have ~75 Mbps from a BT cabinet that I can *just* see if I lean out
of the window.Â* Alternatively I could have up to 500 Mbps from virgin
FTTP where they have what is apparently called a "toby" in the footpath
at the end of my drive, same as this ...

https://www.chatteris.biz/blog/wp-content/uploads/2018/02/IMG_2286-Medium.jpg



I have 26 Mbps from BT FTTC and have never used more than 10Giga in a
month. What on earth DO people do with such massive speeds ?.

my former neighbour putÂ* it quite well: "I have 3 teenage children"

Another issue is online games. It takes longer to transfer a given
packet over a slower speed link. Gamers like snappy responses to their
input in order not to die online ;-)


games ?.

They are the people who should have to pay a big premium.

ZZZZzzzzzzzzzzzzzzzzzzzz

On 10/08/2020 18:04, wrote:
On Monday, 10 August 2020 17:30:29 UTC+1, charles wrote:
I have 26 Mbps from BT FTTC and have never used more than 10Giga in a
month. What on earth DO people do with such massive speeds ?.
my former neighbour put it quite well: "I have 3 teenage children"

One of my neighbours only has internet on her mobile phone.

Her husband and her have 5 children.

Owain


So She doesn't care much for the planet then ?

In article ,
Andrew wrote:
On 10/08/2020 18:04, wrote:
On Monday, 10 August 2020 17:30:29 UTC+1, charles wrote:
I have 26 Mbps from BT FTTC and have never used more than 10Giga in a
month. What on earth DO people do with such massive speeds ?.
my former neighbour put it quite well: "I have 3 teenage children"

One of my neighbours only has internet on her mobile phone.

Her husband and her have 5 children.

Owain


So She doesn't care much for the planet then ?

The chairman (female) of a society I'm involved with has just (two days
ago) had child no 5, in just over 5 years, The message of facebook is
"family now complete". SWMBO's comment: just wait until she has 5 teenagers!

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

On Mon, 10 Aug 2020 17:33:06 +0100, The Natural Philosopher
wrote:

On 10/08/2020 17:28, charles wrote:
In article , Andrew
wrote:
On 10/08/2020 11:19, Andy Burns wrote:
Dave Liquorice wrote:

I can't see them managing to complete the "full fibre" network by 2025.

Is that still the target timescale?

https://www.bbc.co.uk/news/technology-50042720

Why the hang-up with gigabit speeds?

https://researchbriefings.files.parliament.uk/documents/CBP-8392/CBP-8392.pdf


I have ~75 Mbps from a BT cabinet that I can *just* see if I lean out
of the window. Alternatively I could have up to 500 Mbps from virgin
FTTP where they have what is apparently called a "toby" in the footpath
at the end of my drive, same as this ...

https://www.chatteris.biz/blog/wp-content/uploads/2018/02/IMG_2286-Medium.jpg


I have 26 Mbps from BT FTTC and have never used more than 10Giga in a
month. What on earth DO people do with such massive speeds ?.

my former neighbour put it quite well: "I have 3 teenage children"

Another issue is online games. It takes longer to transfer a given
packet over a slower speed link. Gamers like snappy responses to their
input in order not to die online ;-)

Could be the same issue :-)

On 10/08/2020 18:57, charles wrote:
In article ,
Andrew wrote:
On 10/08/2020 18:04, wrote:
On Monday, 10 August 2020 17:30:29 UTC+1, charles wrote:
I have 26 Mbps from BT FTTC and have never used more than 10Giga in a
month. What on earth DO people do with such massive speeds ?.
my former neighbour put it quite well: "I have 3 teenage children"

One of my neighbours only has internet on her mobile phone.

Her husband and her have 5 children.

Owain


So She doesn't care much for the planet then ?

The chairman (female) of a society I'm involved with has just (two days
ago) had child no 5, in just over 5 years, The message of facebook is
"family now complete". SWMBO's comment: just wait until she has 5 teenagers!


And .... they are bunking off school to attend protest rallies
complaining about deforestation, global warming, slow internet,
expensive car insurance, 'lost' (uncool) smart phones, ...

On 10/08/2020 17:19, Andrew wrote:
On 10/08/2020 11:19, Andy Burns wrote:
Dave Liquorice wrote:

I can't see them managing to complete the "full fibre" network by
2025.

Is that still the target timescale?

https://www.bbc.co.uk/news/technology-50042720

Why the hang-up with gigabit speeds?

https://researchbriefings.files.parliament.uk/documents/CBP-8392/CBP-8392.pdf


I have ~75 Mbps from a BT cabinet that I can *just* see if I lean out
of the window.Â* Alternatively I could have up to 500 Mbps from virgin
FTTP where they have what is apparently called a "toby" in the
footpath at the end of my drive, same as this ...

https://www.chatteris.biz/blog/wp-content/uploads/2018/02/IMG_2286-Medium.jpg


I have 26 Mbps from BT FTTC and have never used more than 10Giga in a
month.
What on earth DO people do with such massive speeds ?.


one obvious use case is Cloud storage

Previously one would use a NAS on their homer network.

Now you can buy storage from MS OneDrive or from Googledrive or from
Amazon EC2

so a fast fibre connection means that the cloud storage is juts as fast
if not faster than a home NAS plus you can access your stuff from
anywhere in the world.

Another use case is VPN'ing back to home from a mobile phone over 4g and
soon 5g instead of using a public wifi network. Fibre tends to be
symmetric whereas for ADSL/VDSL/Cable the DL speed is higher that teh UL
speed.

Another use case is several members of the family all streaming UHD
content simultaneously......

On Mon, 10 Aug 2020 17:08:44 +0100, Scott wrote:

It's also complicated by the Universal Service Obligation that is
now
in place for broadband. You have a right to at least a 10 Mbps
service and Openreach or Kcom have to provide it. There are a few
gotchas like a cap on the construction costs.

Just being silly now, but if Openreach claim the cost exceeds £3,400
can I offer to install it myself then put the job out to competitive
tender?

Well I don't think Openreach allow any Tom, Dick or Harry access to
their ducts/chambers etc but I guess you could DIY or contract out
any works that didn't involve access to OPenreach's infrastructure,
say the trench from the nearest chamber to your property so all they
have to do is drop their duct into it.

--
Cheers
Dave.

On Tuesday, 11 August 2020 09:45:07 UTC+1, No Name wrote:

Another use case is VPN'ing back to home from a mobile phone over 4g and
soon 5g instead of using a public wifi network. Fibre tends to be
symmetric whereas for ADSL/VDSL/Cable the DL speed is higher that teh UL
speed.

The kind of fibre service that BT are offering is unfortunately not at all
symmetric. The uplink is time division multiplexed in the same sort of way
that cable services operate.

John

On 11/08/2020 23:28, wrote:
On Tuesday, 11 August 2020 09:45:07 UTC+1, No Name wrote:

Another use case is VPN'ing back to home from a mobile phone over 4g and
soon 5g instead of using a public wifi network. Fibre tends to be
symmetric whereas for ADSL/VDSL/Cable the DL speed is higher that teh UL
speed.

The kind of fibre service that BT are offering is unfortunately not at all
symmetric. The uplink is time division multiplexed in the same sort of way
that cable services operate.

John

I dont think so.

No on uses TDM these days - its all packet switched


--
Ideas are more powerful than guns. We would not let our enemies have
guns, why should we let them have ideas?

Josef Stalin

The Natural Philosopher wrote:

wrote:

The kind of fibre service that BT are offering is unfortunately not
at all symmetric. The uplink is time division multiplexed in the
same sort of way that cable services operate.

I dont think so.
No on uses TDM these days - its all packet switched

He's right ...

Everyone is sharing a single fibre at the exchange-end, one downstream
wavelength gives 2.48 Mbps, a different wavelength gives 1.24 Mbps
upstream, closer to the premises it gets passively optically split for
up to 32 sub-fibres to the premises.

All downstream packets arrive at all premises and the ONT filters out
everyone's but yours, there are timeslots that you get to transmit on
the upstream wavelength to fit your traffic around everyone else's.

Packet switched over 21CN once it gets back to the exchange.

G.984 if you're bored ...

Andy Burns wrote:

one downstream wavelength gives 2.48 Mbps, a different wavelength
gives 1.24 Mbps upstream
Oops, Gbps.

On 12/08/2020 07:30, Andy Burns wrote:
The Natural Philosopher wrote:

wrote:

The kind of fibre service that BT are offering is unfortunately not
at all symmetric.Â* The uplink is time division multiplexed in the
same sort of way that cable services operate.

I dont think so.
No on uses TDM these days - its all packet switched

He's right ...

Everyone is sharing a single fibre at the exchange-end, one downstream
wavelength gives 2.48 Mbps, a different wavelength gives 1.24 Mbps
upstream, closer to the premises it gets passively optically split for
up to 32 sub-fibres to the premises.

All downstream packets arrive at all premises and the ONT filters out
everyone's but yours, there are timeslots that you get to transmit on
the upstream wavelength to fit your traffic around everyone else's.

no.
Not according to what wiki says. Its all wavelength division.

Packet switched over 21CN once it gets back to the exchange.

G.984 if you're bored ...


That is wavelength division multiplexing, not time division multiplexing


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The Natural Philosopher wrote:

no.
Not according to what wiki says. Its all wavelength division.

So the openreach chappie keeps 32 "flavours" of ONT on his van to cope
with different lambdas does he? Or does an openreach ONT have an SFP
slot to accept different up/down wavelength GPON transceivers like
BT/virgin point-to-point fibre NTUs? Answer no it doesn't.

On Wednesday, 12 August 2020 07:55:16 UTC+1, Andy Burns wrote:
The Natural Philosopher wrote:

no.
Not according to what wiki says. Its all wavelength division.

So the openreach chappie keeps 32 "flavours" of ONT on his van to cope
with different lambdas does he? Or does an openreach ONT have an SFP
slot to accept different up/down wavelength GPON transceivers like
BT/virgin point-to-point fibre NTUs? Answer no it doesn't.

That would be silly. How about tunable lasers?

https://www.fibre-systems.com/news/o...ring-fibre-20m

For an operator with an existing GPON network, there are 3 main next generation PON technologies from which to choose.

XG-PON (x=10 G=Gigabit PON) was the first standardized next generation technology. It delivers 10 Gb/s downstream and 2.5 Gb/s upstream (10/2.5G) using a single fixed wavelength in each direction.

The latest standard, XGS-PON (X=10, G=Gigabit, S=symmetrical PON), delivers 10 Gb/s in both directions but also supports dual rate transmission. This allows 10/10G XGS-PON optical network units (ONU) and 10/2.5G XG-PON ONUs to be connected to the same optical line terminal (OLT) port through a native dual upstream rate TDMA (Time Division Multiple Access) scheme and TDM scheme in the downstream. XGS-PON dual rate has a similar cost to XG-PON but delivers 4 times more upstream bandwidth.

TWDM-PON (Time Wavelength Division Multiplexing) is the most advanced and sophisticated of all NG-PON technologies. It adds more wavelengths on the fiber (initially 4 in upstream and 4 in downstream, with more possible in the future). TWDM-PON supports flexible bitrate configurations (2.5/2.5G, 10/2.5G, and 10/10G) and uses tunable lasers that allow operators to dynamically assign and change the wavelength on which a customer is connected. As with any new technology, the cost of tunable lasers is still high. But as innovations improve the technology and volumes increase, the cost of TWDM-PON will come down, in time for mass deployments predicted in 2018 and beyond.

https://www.nokia.com/blog/xgs-pon-m...g-pon-simpler/

On Wed, 12 Aug 2020 07:44:31 +0100, The Natural Philosopher wrote:

The kind of fibre service that BT are offering is unfortunately
not
at all symmetric.Â* The uplink is time division multiplexed in
the
same sort of way that cable services operate.

I dont think so.
No on uses TDM these days - its all packet switched

He's right ...

Everyone is sharing a single fibre at the exchange-end, one
downstream
wavelength gives 2.48 Mbps, a different wavelength gives 1.24 Mbps

upstream, closer to the premises it gets passively optically split
for
up to 32 sub-fibres to the premises.

Or even up to 64 but that starts to limit the range to less than 10
km on a subs fibre. B-)

All downstream packets arrive at all premises and the ONT filters
out
everyone's but yours, there are timeslots that you get to transmit
on
the upstream wavelength to fit your traffic around everyone
else's.

no.
Not according to what wiki says. Its all wavelength division.

Wavelength for the up/down combined streams.
Time for individual connections within those streams.

Are we also being sold a pup again with "1 Gbps capable" connections?
If the down stream is limited to 2.48 G bps and all 32 customers are
trying to fill their pipe surely all they'll get is 2.48/32 ~ 78 Mbps
throughput even if individual packets are signalled at 2.48 Gbps.

--
Cheers
Dave.

On 11/08/2020 23:28, wrote:
On Tuesday, 11 August 2020 09:45:07 UTC+1, No Name wrote:

Another use case is VPN'ing back to home from a mobile phone over 4g and
soon 5g instead of using a public wifi network. Fibre tends to be
symmetric whereas for ADSL/VDSL/Cable the DL speed is higher that teh UL
speed.

The kind of fibre service that BT are offering is unfortunately not at all
symmetric. The uplink is time division multiplexed in the same sort of way
that cable services operate.

John



well the fibre rollout (FTTP) that is happening in my road has a top
tier package which is 900 MB/s *both* ways.....

I currently have VM cable which is 200 MBit/s down and 20 MB/s up...

Needless to say, I will be switching as its also cheaper than VM!

On 12/08/2020 07:55, Andy Burns wrote:
The Natural Philosopher wrote:

no.
Not according to what wiki says. Its all wavelength division.

So the openreach chappie keeps 32 "flavours" of ONT on his van to cope
with different lambdas does he?

In the same way that a single radio tuner can receive the whole VHF
band, no.

Scan all frequencies till the one that is transmitting your MAC, or
whatever, is found..


Or does an openreach ONT have an SFP
slot to accept different up/down wavelength GPON transceivers like
BT/virgin point-to-point fibre NTUs?Â* Answer no it doesn't.

https://en.wikipedia.org/wiki/Passive_optical_network



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'noble' idea. It is not an honest pursuit of 'sustainable development,'
a matter of elementary environmental protection, or a search for
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things do occur that make you shake your head and remind yourself that
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