back to article BT pushes ahead with plans to switch off telephone network

BT is forging ahead with plans to shut its traditional telephone network in Britain, with the intention of shifting all customers over to IP telephony services by 2025. The closure of the public switched telephone network (PSTN) is part of plans by BT toward internet-based voice calls via a fibre network. As such it will be …

Anonymous Coward

Re: Digital Fibre Future

Just to correct. All exchanges were not digital by the mid-1908s (speaking as a telephone exchange engineer from 1982 onwards). The last strowger exchange wasn't removed until 1995 (and then there were the cross-bar and TXE exchanges too). Don't confuse "electronic" exchanges with "digital".

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Re: Digital Fibre Future

Love the mistyped date:

> All exchanges were not digital by the mid-1908s

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Re: Digital Fibre Future

"Yes,all exchanges were digital since the mid 1980's,"

Sorry but that probably should be "all _new_ exchanges were digital since the mid 1980's".

In Europe development on digital exchanges started in the early 1970s when phone companies were hyped about computer powered switches. The only country I know of that saw significant use of those were the USA. The idea was that once you have such a system running, you could just replace the analogue switching matrix with something digital, and you get a completely digital system once that was more economical.

What they didn't take into account were the advances in microelectronics. While back in the early 1970s it was perfectly normal to have a computer with ferrite core memory, it was ridiculously outdated by the early 1980s when development was done. The result was that large parts of those switches were re-developed, based on microcomputers. Those switches then were completely digital and gradually came to service in the 2nd half of the 1980s.

Here's a commercial for a 1970s style analogue computerized switching system:

https://www.youtube.com/watch?v=QgB0KSjC2zg

https://www.youtube.com/watch?v=IbTGVN2VMnQ

Ohh and here's a BT film about their development of ISDN switches

https://www.youtube.com/watch?v=xy_6DL4haJA

There's even a 1984 Japaneese childrens programme about I(S)DN. Here's the German dub of it:

https://www.youtube.com/watch?v=4sCuN6TE8y4

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Childcatcher

"...where broadband rather than voice becomes the primary service"

So what about the recent announcement about "cheaper" line rental for "customers who do not have broadband"? Everyone must now take broadband (by 2025)?

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Anonymous Coward

Manx Telecom migrated already

https://www.manxtelecom.com/about/media/press-releases-2016/3048-manx-telecom-continues-investment-in-fixed-line-network

They had a few teething problems, including a noticeable slow down to consumer broadband, which seem to have been sorted.

Alcatel backbone, which MT were a guinea pig for IIRC.

Similarly rolling out fibre to premises soon too.

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Holmes

So what about the customers?

If we're looking at VOIP and digital-only to the premises, who's going to pay to make my analogue interfaced cordless system a VOIP compatible one? Who is paying for my mum's new digital phone? Physical lines and infrastructure "owned" by Openreach are one thing, the millions of pounds of existing analogue hardware owned by domestic customers that would need replacing is another.

Perhaps there'll be a ten year gradual changeover period like DTV?

Thinking about this needs ...

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Re: So what about the customers?

You can already buy routers that have old-fashioned analogue telephone sockets on them. You plug your old phone in there, and the router converts the signal to VOIP for you and sends it over your Internet connection. So all you need is a new router, which isn't that expensive or that complicated.

This is about BT getting rid of PSTN at their exchanges and on the wires to you, so they only have to terminate one (Internet) signal instead of two (Internet+PSTN) signals. This makes things cheaper for them. They don't care whether or not you continue using PSTN inside your house.

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Re: So what about the customers?

"So all you need is a new router, which isn't that expensive or that complicated."

Except when you multiple it by the number of households in the UK - then it becomes ferociously expensive.

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Unhappy

Re: So what about the customers?

"who's going to pay?"

Well, on one side you have BT, well known for pinching pennies wherever they can, and on the other side you have their customers, most of whom are locked in and have no other option but to pay whatever BT charges.

I think we can all guess who'll end up paying.

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FAIL

Re: So what about the customers?

"Perhaps there'll be a ten year gradual changeover period like DTV?"

This is an ongoing ballsup. Every year or so Ofcom fuck it up. Why did I lose BBC4HD signal with no warning 3 weeks ago. Because Ofcom can piss about without a thought for the end users.

Please take the wankers out the back and shoot them. If it is a problem for me and I am IT literate, what about the millions of other punters who cannot use Google properly.

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Anonymous Coward

Re: So what about the customers?

"Except when you multiple it by the number of households in the UK - then it becomes ferociously expensive."

Offset by the savings made from switching off 5500+ pieces of 80s technology and the entire TDM based transport network. Tons of cash saved in power and cooling.

If Openreach finally deliver a massive FTTH network, then it doesn't matter. They'll need to deploy ONTs (the FTTH "modem"), and they'll stick the phone hardware in that - as they already do for the lucky few who can get Openreach FTTP today. Even bigger savings there as they can switch off the DSLAMs too!

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Re: So what about the customers?

"If we're looking at VOIP and digital-only to the premises, who's going to pay to make my analogue interfaced cordless system a VOIP compatible one?"

First of all, my condolences for that piece of kit. You should sue the person who sold you that... but I digress...

In Germany the scenario for old, so called ANIS lines (essentially people who still rent their Dialphone for an Euro a month) is simple. You install a special line interface which is essentially an ATA so you can have all your analogue goodness like Impulse dialing, static, echoes and even semi-broken signaling so your answering machine will record some noise or beeps when the caller hangs up.

For people who want to have Internet along with ISDN, there's not much change. The most popular routers people buy in Germany already include a very decent VoIP stack you can plug your ISDN phones into (or even dialphones if you insist), and they even include a DECT base station. If you are one of those customers renting the CPE and you don't have the necessary equipment, you'll get CPE with at least one port for your dialphone. Some telcos in Germany, like Deutsche Telekom, are known for extremely shitty CPEs.

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Anonymous Coward

Wither the 21CN?

Hang on a minute, weren't BT ballyhooing "broadband dial tone" fifteen years ago as part of the "21CN" project? What happened to that?

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Anonymous Coward

Re: Wither the 21CN?

BT (largely but not exclusively Openreach) had two largely independent flavours of 21CN, though the 21CN publicity often muxed them ip.

One flavour was for mass market broadband via xDSL, which was (sort of) planned, rolled out, and by now is mostly superseded.

The other flavour was "21CN Voice" (see e.g. https://www.theregister.co.uk/2006/11/28/21cn_online/ which relates to BT's first public implementations of 21CN).

See also e.g.

http://www.comms-dealer.com/industry-news/bt-ends-phase-1-21cn-voice-trials-network-closure

21CN voice rollout was "suspended" shortly thereafter, and in due course, abandoned.

Hopefully the people who f***ed up the 21CN Voice design will have moved on by now.

So this most recent announcement is presumably 21CN Voice V2.0?

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Re: Wither the 21CN?

"What happened to that?"

There's still a lot of the C21st still left. Plenty of time. And besides, the marketroids who thought it up have probably moved on.

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Seems to be the obvious thing to do and has been for decades.

I'm almost at the point of suggesting that 999 call-handling should have some rule-changing, to be honest.

Everything in my workplace is IP - from the phones on the desk, to the fax machine, to the GSM alarm systems to the SIP trunk. There are no longer any analog or ISDN lines or anything of the sort still active, because there's no need for them to be and they have disadvantages despite being actually on-the-premises still.

Its seems only logical to plan for an IP-only future in terms of telecoms, even things like video, mobile telephony (all modern handsets do SIP, so the 4G etc. network is really only providing a data backend), etc.

I imagine it means a lot of clutter removed from exchanges and only legacy lines having a kind of conversion equipment, which can be phased out by moving everyone to "proper" fibre connections as necessary.

It just makes much more sense.

The get-out-clause also disappears from BT's books - they can't just blame demand for not having cabled your area properly yet. If you have all-IP exchanges and all-IP cabinets, there's no reason that some manky old line can't support stupendous speeds even if it's shared with the rest of the village once it gets to the exchange. That won't stop them trying, though.

I can quite easily believe now that there are households and businesses all over the country that are pretty much IP-only, internally and externally, for everything from telephony to CCTV.

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Everything in my workplace is IP

Pretty much everything is in my workplace too, which leads to such idiocy as all of the sites having a Cardiff 029 dialling code. Bear in mind that we have seven sites and only two of them are actually within the Cardiff area code. One is in Llanberis, at the foot of mount Snowdon. It does sort of confuse third-parties.

I'm sure there would have been a way around it, but while in the past each site had a local exchange and ISDN30 bundle, much money was saved by only having (effectively) one SIP gateway and one telephone code.

M.

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Do people still seriously rely on dialling codes to identify areas? Today we have non-geographical numbers, we have number portability. Using area codes is like trying to geolocate using nothing but an IP address.

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"I can quite easily believe now that there are households and businesses all over the country that are pretty much IP-only, internally and externally, for everything from telephony to CCTV."

And a lot that aren't. But yours is so you're OK and the others don;t matter. Or did I miss something?

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Do people still seriously rely on dialling codes to identify areas?

Speaking personally, if I want a local plumber and all I've got to go on is the number on the side of the van I saw parked outside next door, I'd call someone with a local (or neighbouring) area code before I called anyone with just a mobile number. Not seen this kind of sole- or small-trader use non-geographic codes; they cost real money for very little benefit unless you genuinely are a national company.

As for my place of work, it genuinely does confuse people. If a teacher at a local school wants to talk to an education officer at their local museum and is given a direct-dial number which appears to be for a site 150 miles away, they're going to wonder if the person they are speaking to is the person they really need to speak to. I don't deal with teachers, but I do occasionally have suppliers ask "can I just check I've called the right number?"

Yes, we do have a non-geographic too. 0300 as it happens, but you can't do direct-dial on this one.

M.

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will my pulse dialing rotary phone still work?

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Unhappy

Bad news for you... it doesn't work now. That stopped working when they deployed 21CN a few years ago (putting the timescale in context, it coincided with updating the exchanges from ADSL to ADSL2+).

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Bad news for you... it doesn't work now

Mine does. I have a pulse-dialling rotary phone and it works just fine. Except for those pesky automated sites that ask you to "press 1 for sales" or whatever.

Before buying it (as a birthday present some years ago), I checked by "manually dialling" 1471 using the hook switch (yes, it's possible).

I'm told that some third-party POTS providers don't accept pulses and I have no idea about VoIP - POTS gateways, but our line certainly does.

M.

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Bad news for you... it doesn't work now

Well it must be haunted then! admittedly when it rings i just pick the doodah up and drop it again - but i do use it occasionally to labouriously dial my mobile to locate it.

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Anonymous Coward

"Bad news for you... it doesn't work now. That stopped working when they deployed 21CN a few years ago (putting the timescale in context, it coincided with updating the exchanges from ADSL to ADSL2+)."

It will work. 21CN for voice was effectively abandoned except for the areas where it was trialled (and GPO's finest were on the list of devices that BT had verified to work). The rest of us got put onto 21CN for broadband but the voice still comes from the same old "20C" switches.

It'll even work if you're lucky enough to have Openreach FTTP, where your phone line is VoIP and is delivered from the ONT.

YMMV if your phone services comes from someone else's kit - but I've seen reports from TalkTalk customers that their GPO 746 works just as well as it ever did.

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cb7

Voice quality

Almost everyone seems to have missed the fact that VoIP sounds shite or is totally unusable if broadband latency/jitter is too high - doesn't matter how many mbps you get.

Plain old telephony (POT) on the other hand always sounds a lot clearer and without any delays compared to VoIP / mobile.

I've got an Infinity2 line that goes at ~70Mbps down and ~19Mbps up with 15-30ms ping times typically and WhatsApp voice calls often exhibit long delays in transmission to the point where you end up talking over each other as the other party thinks you haven't said anything. Reverting to a POTs line brings refreshing reliability and clarity in comparison.

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Silver badge

Re: Voice quality

Most mobile calls use an enhanced codec and sound far better than landline. Well at least in the southeast. It's quite jarring to suddenly have to make a call to a landline and I notice the drop in quality.

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Re: Voice quality

VoIP sounds shite only if you don't bother to QoS.

A VoIP channel is TINY in terms of bits-per-second. Sure latency will delay things. Jitter will make it wobble. But those don't tend to matter for a... what? 64Kbps stream over a 10Mbps channel? That's a HUGE amount of loss before you're affected. Latencies of 100ms on voice traffic are not noticeable and if you have more than 100ms ping to even the other side of the planet, you have bigger problems on your connection.

But what matters is that your phone call doesn't get superseded by Fred over in the office loading his Facebook. His packets can wait, and he'll never notice. Yours can't.

It's very easy to demonstrate. When a workplace first gets a VoIP phone in-house, warn them that it will happen. You can put in the most expensive switches in the world and massive redundant fibre connections and all sorts, and even on switchboard-only calls, it'll work. For one phone. Two phones. Three phones. But before you even get into silly numbers (say a dozen), or if there's a particular time when everyone logs in... the phones will start to distort and cut out. It doesn't matter how much money you throw at it at that point.

At that point, everyone starts getting rubbish service and it sounds bad. So you VLAN off the voice traffic, and apply QoS to it. Now watch as you can go to 100, 200, 300 handsets and no problems. On the same networking, the same expensive (or cheap!) switch. The same Internet line.

The problem with telesales people on VoIP is either that they don't have the IT people to know this, or they are all working from home over their home ADSL router (more common than you might think... lots of people do telesales jobs from home, dial into the switchboard from a phone they are given to plug into their router, and off they go). Nobody sets QoS properly. And it affects NOTHING else when you do it right, while making the phones all "just work". I've demonstrated this phenomenon on everything from the cheapest Netgear to the most expensive Cisco, with less than a dozen phones each time. Works fine at first, then ordinary network usage interrupts it and it fails. Apply QoS on the same switch and then you can expand enormously without issue.

I've seen contractors who carry around Ethernet IP phones and just plug them into people's networks expecting it all to magically work... and invariably they say it works where the IT is well-managed and doesn't anywhere else they try it - even if they're the only person on the network. Because the QoS isn't automatic.

And QoS applies not just to the local network, but to your wireless ("Airtime Fair Sharing") and outgoing packets too. Your router has to know to deal with the voice packets FIRST before it worries about your Counterstrike game. It has to respect QoS and pass it on (it'll likely be ignored by the ISP, but you never know) just the same as the switches. Your Whatsapp traffic isn't QoS'd because I think it goes out over untagged encrypted protocol which your smartphone / wireless / router doesn't understand or respect. That's why it does that.

The number of times I've had calls FROM people selling me VoIP where I literally can't hear their call (and it's not us... at various places and times I've had analog, ISDN and SIP so we know our calls were clear).

When we started buying local IP handsets, the problem came within a dozen and I QoS'd and four years and a hundred handsets later we're fine. When we started going down the line of SIP trunking, I did the same - made sure the traffic was VLANned, that entire VLAN was QoS'd on the switches, prioritised on the router, firewall and wireless points. Made sure that the outgoing SIP ports were forced to max priority so they retained that QoS when they went out to our ISP, etc. Literally never had a problem, even with user's maxing out the connection on an hourly basis.

Voice traffic doesn't care about bandwidth and retransmission, like other technologies. TCP will just "try again" so fast that you'll never notice a problem. But VoIP needs to be jumping the queue for every tiny little packet it sends because it NEVER tries to send it again, it's already too late by then. If it can't jump the queue - from the phone to the network to the switch to the firewall to the router to the Internet - then it will be bad. If it can jump the queue, it's literally so miniscule that nothing else will notice or care. The actual bandwidth it consumes is pathetic.

To be honest, even "wireless" IP phones have more problems than cabled ones. Because you can't stop someone on the same channel but another SSID or just plain interference from "jumping the queue" and holding up the voice traffic.

If you are expecting VoIP and you're not in control of QoS... you're on your own. It might work, it might not. If you are MANAGING VoIP - apply QoS from day one on everything in the path. Then, quite literally, you can run a entire company switchboard from a dodgy old ADSL line.

As an aside, we abandoned all our analog and ISDN lines last year, after many years of waiting for approval to do so. They were more likely to provide poor performance (everything from rain affecting the cables, to things literally falling off the telegraph poles) and we had more faults on ISDN than I care to remember. We retain one emergency line only so we can dial 999 if the system goes off. But everything else is entirely SIP. I haven't had a complaint about call quality for a year.

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Re: Voice quality

There are some providers insisting on G.729, that's when you get shite voice quality.

Any semi-decent one will give you G.711 which is (except for a bit more latency) indistinguishable from ISDN. However even the latency should be much lower than 150 ms end to end. If it's not you or your ISP are doing something seriously wrong. Typical problems include not traffic shaping the Uplink and not prioriticing UDP.

Any decent telephony provider will tollerate no more than a single packet being dropped per 10 minute telephone call.

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BT have finally realised the value of their copper on the scrap metal market, as predicted by El Reg!

https://www.theregister.co.uk/2011/09/22/bt_copper_cable_theft/

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TRT
Silver badge

Next thing you know...

they'll be culling off all the FM radio transmitters in favour of DAB!

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Anonymous Coward

Re: Next thing you know...

My DAB comes from transmitter that is much closer than the FM transmitter. I use DAB to get the "now playing" data from Classic FM - except that often they just have a line saying "go to our web site".

Radio 4 comes from FM as it is a more reliable signal. The DAB Classic FM often burbles or goes off for periods.

No incentive to lose FM here.

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Re: Next thing you know...

Ah DAB, that stands for Diabolically Awful Broadcasting I believe.

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Re: Next thing you know...

That is going to happen in the end. Norway has shut down most of its fm broadcasting system already in favour of DAB+ broadcasting.

BBC seems to be against turning off fm transmitter network.

http://www.bbc.com/news/entertainment-arts-43458695

The thing about DAB+ is that they use VHF (175 - 233Mhz) and that needs stronger transmitters to give good coverage. FM is at 87,5 - 108.0Mhz.

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Anonymous Coward

I see people are highlighting 999 calls, fear not, by the time this is done there won't be any police etc.. left due to cuts.

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Facepalm

I see people are highlighting 999 calls, fear not, by the time this is done there won't be any police etc.. left due to cuts.

More immediately, the 999 services are going to be moving from TETRA radios to 4G on EE, so even if you could call the emergency services without a mobile signal, the controllers won't be able to talk to the fire engines or ambulances...

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Unhappy

Just imagine...

You and your lovely wife are out for a romantic long-weekend in the Scottish Highlands. It's been years since you had any quality time together, what with bringing up the kids and working all the hours that God sends. But hey, the kids are older now, and the grandparents are delighted to spend a little time with their grandchildren, so this trip is just the ticket.

The weather, however is terrible. Gale-force winds and punishing, driving rain, and the late hour are doing their best to take the shine off the occasion, but both your spirits remain high. It's only another mile to the holiday cottage that you've rented, so there's no way you're stopping now.

On the B874, between Janetstown and Shebster, with the wipers on maximum, peering through a semi-fogged screen, you hit the brakes hard when you suddenly notice an old broken farm trailer, abandoned at the side of the road. It's clearly been there for years. The front of the trailer is parked well enough, but the back end is hanging out over the verge, into the road.

Screeching tires, a terrifying smashing sound, sparks, and then... Black.

You awake goodness knows how many minutes later. Or was it hours? A nasty cut on your head has already started to congeal. It hurts, but you'll be alright. You look to the passenger side.

"Are you alright Sarah?"

"Sarah?"

"Sarah, can you hear me? Are you okay?"

Silence.

Gently, you turn her head towards you. The left side of her head is smashed in. Eye socket gone. Massive blood-loss. The trailer bed had come through the windscreen and... well, you know the rest.

You check her pulse. Yes! She's alive. Okay. Hold it together. It's important not to panic. You know where you are because you're only a mile away from the house and you have the address in your wallet.

You reach for your mobile phone. 999.

Nothing happens.

Shit! No signal.

Now what? You look around for lights. There must be a house somewhere near. It's only 9pm. Somebody will still be up.

Nothing.

"There's nothing for it", you say to yourself. "I'm going to have to get to the cottage and raise the alarm myself".

You set out into the howling wind, leaving the hazard warning lights on.

After about 15 minutes you reach the cottage. Well, presumably this is the right cottage. You slip the key into the lock. The lock turns! Yes! Stepping into the hall you find the lightswitch and turn on the hallway light. Nothing. Damn it. There must be a power cut.

Using the light on your mobile you find the phone on an old-fashioned three-legged corner-table just behind the living room door.

You pick up the phone. Wait for the dial tone.

And wait.

And wait.

You check the phone socket on the wall. It's one of those new VOIP RJ45 phone sockets, and right next to it, under the phone, on the floor is the router, plugged neatly into the phone and a nearby mains socket.

And there's a power-cut.

That's when you realise. You are alone. Totally alone. The only thing that can now possibly keep your wife alive, is you.

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Anonymous Coward

Re: Just imagine...

People downvoted that post. Let me give you a true story:

In Donegal back in the late 1970s, many of their local exchanges were still manual. You picked up a phone, waited for the operator to answer, and asked for the number you needed. The operator in rural areas went home in the evenings, there was no phone service until the following morning. A friend of ours woke in the small hours to find her husband in distress, he was having a heart attack. She was 8 months pregnant, and had no way to call for help. She struggled into the car and went for the doctor, but by the time they returned her husband was dead. Without working emergency phone service she not only couldn't send for help, she couldn't even stay with her husband to comfort him while help might have arrived.

Automatic exchanges with 5- or 6-nines reliability have removed that nightmare from rural lives. Does anyone serioulsy think that VoIP can come even close to offering that sort of reliability??

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Thumb Up

Re: Just imagine...

Come on man, you can't leave it there. I want more. The novel / screenplay you are writing is great. When is the next chapter..... Does Sarah live or die? I gotts ta know.

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Silver badge

Re: Just imagine...

The front door slams open behind you. You think it's the wind, and you turn round, reaching out to shut it again against the raging storm, when silhouetted against the lighting illuminated solid rain downpour, the outline of Sarah. But not the Sarah you knew, this one is dressed in a sopping, torn dress, head lolling on one side, vacant staring look in her one remaining eye. You take a step forwards, but then recoil as she raises both arms and shuffles forwards, letting out a dull moan, her teeth gnashing together in a slow, biting, chewing motion... Are those words she's trying to form? "Brainnnnzzzzzz...."

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Anonymous Coward

Re: Just imagine...

ForthIsNotDead,

You have just won the 'Internet' for the most artistic & longwinded way to make a point. :)

Totally agree with the point.

Once again BT promises the 'World' and no doubt will deliver a 'Plastic Glow in the Dark' World Globe, 5 years late and at 3 times the price ....... UNLESS BT are 'implying' that there will be 100% mobile coverage 'before' this is delivered.

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No extra charge for spooky stories?

Really??

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ISDN?

We still make occasional use of ISDN - it "just works" when the local radio station comes around, in a way that their IP-based WiFi or 4G OB system doesn't when two thousand people are connected to the same AP / mast. We once tried ISDN over IP. It "just didn't work".

I suppose if we upgrade and allow them access to our wired network it would be ok...

M.

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"BT killed my family"

I don't know how they will respond when the change inevitably results in death which would likely have not occurred if they had stuck with what we have.

I imagine this might also be in the minds of those who have to approve the change.

With the issue being one of public safety I am inclined to think the risks outweigh the benefits. Failure modes are easy enough to see so the onus is on them to convince us they are not a problem or are an acceptable price to pay.

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Black Helicopters

Does anyone know

If my (backup iun case of power-cut) battery powered dial up modem will work over a VOIP connection?

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So what happens to people on broadband?

Is it a case of "lol, sucks to be you, huh?" from BT or do they delusionally believe that everyone will be FTTP by that point?

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Thumb Up

This will do wonders for BT's number of complaints. Those with bad/or no internet won't be able to phone BT to complain about it.

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Landline?

How quaint

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