Grandma's Phone, DSL, and the Copper They Share (hackaday.com) 177
szczys writes: DSL is high-speed Internet that uses the same twisted pair of copper wire that still works with your Grandmother's wall-mounted telephone. How is that possible? The short answer is that the telephone company is cheating. But the long answer delves into the work of Claude Shannon, who figured out how much data could be reliably transferred using a given medium. His work, combined with that of Harry Nyquist and Ralph Hartley (pioneers of channel capacity and the role noise plays in these systems), brings the Internet Age to many homes on an infrastructure that has been in use for more than a hundred years.
What year is this? (Score:4, Insightful)
Re:What year is this? (Score:5, Funny)
According to my prof in 1987, doing a paper on Shannon's work puts you back in 1959. (Fuzzy logic was his thing, in 1987.)
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The scary thing is I believe a lot of people likely still use it because that's all they can get.
Viable still applies if it's being sold, and lot of people are on it.
According to this [digitaltrends.com] (which is from 2013), 18% of American internet usage was on DSL.
I don't think "viable" means what you think it means. Used by tons of people and still actively sold ... well, it's outdated, but it's still viable.
Re:What year is this? (Score:4, Interesting)
I'd be thrilled if I could get DSL.
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First ... you poor bastard.
Second ... exactly my point.
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Well, fixed wireless broadband isn't *horrible* compared to some alternatives. I went from DSL to 28.8k dial-up for a few years and that was... well, I didn't worry about congestion from neighbours, that's for sure.
The only advantage of fixed wireless over DSL or cable is that I don't have to worry much about where I put holes in the ground; the only line coming onto my property that I care about is overhead.
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And even if you get DSL you may not get the best DSL either. Older neighborhoods may be really bad in this regard.
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I say this assuming you are in what is typically called the last mile rather than the actual last mile so far from civilization where there are no phone lines and sat communications are your only option. If you are in the arctic or at sea DSL capabilities may indeed be reasonable. To a point anyway, there is
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I have a choice of broadband wireless providers (two that I know of), or satellite broadband. Or I could use cellular service for the week or so before I maxed it out.
I suspect in a few years I might be able to get fiber, depending on what they're doing with those lines they ran down the highway at the edge
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All true. Fortunately, billions of dollars have been provided to telcos making deploying that fiber free and local government grants them immunities and eminent domain protections allowing them to lay out those lines without property owners having a say in the matter. Telcos however are required to build that inf
Re:What year is this? (Score:5, Funny)
I'd be thrilled if I could get DSL.
Your Internet connection is so bad, you only have enough bandwidth for one letter in your username.
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I s
-*- click -*-
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Though his child, c++, has better connectivity.
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I'd be thrilled if the DSL here was rated above 1 Mbps.
Instead I get 10 Mbps cable with a low GB-per-month cap, that have actively hijacked google's DNS record to point to their own . . . I dunno, local cache or something. HTTPS Everywhere kept me from noticing for the last month.
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According to this [digitaltrends.com] (which is from 2013), 18% of American internet usage was on DSL."
That's only true if those people have a legitimate choice and weren't duped into picking an obsolete slow connection by a monopoly refusing to modernize.
The article mentions 6mbps, that isn't fast enough to support many modern and common household internet usages which means customers are being sold a system which is not viable. You migh
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The article mentions 6mbps, that isn't fast enough to support many modern and common household internet usages
Like what? It's enough for TV-quality streaming video, web browsing, VoIP, email and all the usual stuff I can think of.
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The article mentions 6mbps, that isn't fast enough to support many modern and common household internet usages
Like what? It's enough for TV-quality streaming video,
No, this must be one of the few times where they actually mean 6 MILLI-bits per second (mbps) and not 6 MEGA-bits per second (Mbps). Six mbps means you get one character every, umm, 27 minutes. Six Mbps would be fast enough for streaming all kinds of things.
Re:What year is this? (Score:4, Informative)
It all depends on how far you are from the nearest central, 3-5 km out on basic ADSL is pretty crap. If you live close to the exchange or they've pulled fiber "close" and you get ADSL2 or VDSL you can get decent 10-50 Mbit. No doubt the growth is fiber though, here in Norway it's now 28% (+6%) fiber, 22% (-5%) DSL since last year.
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It is. Plenty of things don't need more than the 5-10 Mbps you can typically get with ADSL, and if that's not enough there's VDSL2 which gets you tens of MBps.
Besides, cable and especially FTTH are much less widely available.
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True, which is why billions of tax dollars have been given to the major telcos to effectively make digging all those holes and running those lines free. Additionally, they are granted special exemptions from local government, allowing them to tear up property or run along poles over property without paying the individual owners of the property. When taking this money and special exemptions they function as telecommunication providers, the justification for the benefi
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Yep, and in my apt building we have fiber to the basement and G.fast DSL (1Gbps) up to the unit.
Even if we opt out of that full 1Gbps, we have the option for 100, 60, 40 and 20Mbps DSL.
To contrast, the cable company can only deliver 10Mbps into our unit. I tried it for about a day before I canceled that service... I was effectively getting only 2Mpbs.
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What the hackaday people need is an ISDN line.
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No, it isn't.
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How is paying to the evil telco better than paying to the evil cable company?
The issue is not so much what you need as being entitled to the best access that can reasonably be provided. If you currently have 12mbps dsl (which should be delivering 12mbps) then there is absolutely no reason you shouldn't
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And SD is not worth watching.
I don't get that logic -- if it's a good movie, it will still be a good movie in SD. If it's a bad movie, it will suck even more in HD.
The subset of movies that are worth watching in HD but not worth watching in SD must be very small -- Avatar, maybe?
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Can't speak for netflix but SD video is definitely worth watching. Who cares? A computer monitor isn't a giant TV.
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If this is the direction that Slashdot's new ownership is taking the site, it's still better than the barrage of constant articles meant to bring out the sjw/anti-sjw trolls, or articles about Trump's verbal flatulence, or *shudders* anything by Bennett.
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It's an hack (Score:3, Interesting)
Would have been nice if DSL never existed, dial-up would be the norm and websites would not be bloated, no social media or other bullshit.
Instead companies keep profiting while not investing anything into upgrading the rotting copper.
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Yeah! They should have never started selling 1TBps fiber connections. We wouldn't have all these holovideos, remote windows and HD video ads that can't be muted. Most people don't even have their own computers anymore they just buy these mini-terminals and pay $10/mo applecorp for time on the applecore mainframe system.
Yep If no one had ever bothered to build the infrastructure lots of things like youtube, netflix, remote surgeons, drones, video calling and working from home wouldn't be possible today.
But y
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Nah, ANSI or RIP art. ;)
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You can still use dial-up these days if you still have copper lines. :P
Are we newbies? (Score:2)
I mean this history lesson is fascinating, but really, I think most of /. knows how DSL works alongside voice on POTS.
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Yep we do.
My problem is At&t.
They want to run VoIP over my DSL line over my POTS line.
Sounds reliable don't it?
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You mean, they want to run VoIP over IP? How rude.
At&t should allow for a dedicated low bandwith link with end-to-end connection, so you can run your VoIP without bad quality, jitter and lost packets.
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Yeah as of now I have POTS with phone > DSL modem > router.
They are trying to get me to switch to POTS no phone > DSL modem with voip bridged back to pots line > router
As of now I can lose phone without losing DSL and I can lose DSL without losing my phone.
So then If my dsl goes down I lose both internet and phone.
They've been advertising it as fiber optic phone service.
Sigh. (Score:4, Insightful)
Looks like the new owners of Slashdot are also failing to combat the biggest problem faced by the site for the last few years.
Junk making the front page that talks to me like I don't already work in IT or understand how common household technologies work.
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You do understand that Slashdot has users from a wide variety of backgrounds? If you don't like it, scroll on by.
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Junk making the front page that talks to me like I don't already work in IT or understand how common household technologies work.
Who are you? I didn't understand how DSL worked until I read the article, now I do. (Well, probably not, but now I know more than I did)
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Disagree (Score:4, Insightful)
I disagree.
Not everyone here studied this stuff. Some of us are self taught, or are experienced in other fields (software, systems admin) ...etc.
So, having stuff like this is enriching to some here, and relevant to the site ...
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Cable is still copper and some areas have old (Score:2)
Cable is still copper and some areas have old plants that some of the big guys like Comcast are not really upgrading that much.
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Are you sure it's not lead sheathing around copper conductors? This was common for noise insulation and waterproofing - but I'm surprised that they would use lead conductors.
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Claude Shannon (Score:5, Informative)
Claude Shannon was truly one of the unrecognized geniuses of his time.
He was an amazingly brilliant man who got very little of the recognition he deserved. Virtually ALL modern-day communication depends directly on the algorithms and information theory practices he invented. He's quite rightly known as the "founding father of electronic communications age".
He was still alive when I was in tech school, quite literally a "living legend".
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Claude Shannon was truly one of the unrecognized geniuses of his time.... He was still alive when I was in tech school, quite literally a "living legend".
Not sure how old you are, but he was apparently one of the *recognized* geniuses of his time. He has a long list of awards dating back to an AIAE 1940, a National Medal of Science in 1966, to the Kyoto prize in 1985 and quite a few lifetime achievement awards since that time...
You don't get that type of swag and get to claim to be unrecognized (not that Mr Shannon was the type to crave any recognition, by some accounts he didn't really care for the stuff)...
On the other hand, Rosalind Franklin, Emmy Noethe
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Let's not forget (Score:2)
Let's not forget that there was also the option of running high speed internet over the power lines. It does mess with Ham operators signals, though, so is not widely adopted. But in areas where it is adopted, people seem pretty satisfied.
Look at what you can do with a single coaxial wire (Score:2)
Forget twisted pair. I have hundreds of cable channels and a 25 Mbps internet all brought into my home with a single coaxial wire.
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Twisted? Luxury!
I worked on some of this. (Score:5, Informative)
Many *MANY* years ago I was working as a software engineer at Philips Research in the early 1980's when they were looking into ISDN systems somewhat like DSL for the UK market - the business of sending anything over twisted pair copper is a nightmare. I wasn't directly working on the electronics (I was doing software) - but I shared an office with people who did...and they had a heck of a time characterizing the wires that their signals had to go down.
As I recall, the problems mostly come where one wire is spliced into another. Much of this infrastructure was put in the 1900's and it's horrible. Sometimes wires are just twisted together and capped, sometimes twisted and taped, sometimes twisted and just left open to the elements, sometimes they are soldered. Sometimes the places where the wires are joined gets wet when it rains. Sometimes the tightness of the twisted wire connection depends on the ambient temperature. The amount of cross-talk between wires is all over the map as different kinds of insulation was used (and much of it has degraded over the years). At the subscriber end, there were all kinds of phones being used - plus ugly stuff like "Party lines" (where two houses share a phone line!) that had been abandoned leaving extra wires in the ground that were still connected to the network.
All of those things affect the ability to get a decent amount of bandwidth down a wire that was never designed to do it. So the electronics has to be smart about the signal being reflected at each splice down the line and causing 'echoes', and designing affordable circuitry to detect and cancel those echoes was a nightmare. The amount of attenuation you'll get is all over the map - everything has to self- adjust and monitor to give it any chance of working.
So, as poor as DSL can be - it's a miracle it works at all over crappy old telephone wires.
-- Steve
Phone portion goes unused (Score:2)
These days in my country at least the router/modem provided by the ISP has a connector to plug an old (or new) land phone in, but it goes over VoIP. You have an RJ11 to phone plug adapter if needed.
"Real" POTS is something you would have to look for, likely from the former monopoly ("historical") operator. Or maybe in a few areas left where things still have to go through the historical operator even when your ISP is something else.
BTW grandma has had a DECT cordless for a while. Also, a permanently seated
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Out of interest which country? Here in the UK phone service is still usually delievered over "real POTS". ADSL and VDSL (FTTC) users use filters/splitters to seperate voice and DSL. The cable company runs phone wiring alongside the cable TV wiring (and have done so since long before the days of cable modems).
FTTH services may be an exception but those are still pretty rare here.
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France. I should have been clearer maybe, it's POTS lines and the filters/splitters, but I believe the ISP may not bother providing the plain voice service.
F#$^#$^@ (Score:4, Funny)
My grandmas are dead, you insensitive clod.
Uhm. What? (Score:3)
And I stopped reading bullshit article right there...
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No, but it was used in the original post reporting the article...
is that actually high speed (Score:2)
Does 6mbps actually qualify as high-speed anymore ? I thought Congress/FCC decided it had to be like 50 mbps to be called high speed ?
Re:Everyone's phone, DSL and copper (Score:5, Insightful)
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Re:Everyone's phone, DSL and copper (Score:5, Informative)
Actually it won't. Not unless your grandmas phone was touch tone and 80 years ago it certainly wasn't.
You may not be able to place calls with a rotary phone any more, but you certainly can receive them. The system still works, its just the dialing methods have changed.
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You may not be able to place calls with a rotary phone any more, but you certainly can receive them. The system still works, its just the dialing methods have changed.
Actually you can, atleast in the UK. Pulse dialling is still supported by the national phone provider.
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I guarantee the US can, too, as it's all computers now.
My dad refused to give up his rotary (a phone company rental bakelite black, at that) because the phone company continued to want to charge extra for "premium" touch tone service, even long after it was actually a drag on them.
Last time I had a land line, around 2010, it was rotary-only, so whenever I had to use a menu, as to pay a bill, after dialing I would switch the phone to touch tone.
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Read the article. It's explained, there.
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You could still play DTMF tones through the handset to dial the call, so it's just an extra tool required to place calls.
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LOL. Is there an app for that? I was always amazed by those modems that you put the handset onto some microphone thing? (Slightly before my time, so I only saw them in the movies, I started with a 2400 baud ISA modem...)
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Audacity (the audio editor) even has a built in tone generator that will do DTMF.
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I don't know where you live, but here in Canada me and my father tried a 30 years old rotary phone on his landline a month ago and it worked perfectly, to our amazement.
But I have serious doubts it would work on my "land" line, since it's really just a cell base station with a SIM card.
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Re:Everyone's phone, DSL and copper (Score:5, Funny)
Not unless your grandmas phone was touch tone
Pulse dialing still works nearly everywhere. Indeed, some people are skilled enough to do pulse dialing by flashing the hook the required number of times.
Like me.
Get on my level.
--
BMO
HOWTO: http://www.oldskoolphreak.com/... [oldskoolphreak.com]
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In many places in the U.S., pulse dialing still works.
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But literally the *same* wires inside the house have been used for pre-rotary dialing as well as DSL. Though of course DSL speeds depend a lot on quality of wires outside the home.
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We have to dial 1 to make a long distance call and have to dial the area code even for local calls but pulse dialing still works here in oklahoma.
Re: Everyone's phone, DSL and copper (Score:2)
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I still keep a landline for emergency, it's never failed in 40 years.
Of course, the flip side of that is that you're likely paying a significant monthly bill to keep that reliable land line active.
My building's two front-door call boxes were each using a land line for their call-up function, and they were costing the HOA $65/month each. I switched them over to VOIP, now they cost the HOA about 25 cents per month each (not including the $23/month DSL service, since we had that set up anyway for unrelated reasons).
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And even if the local loop stayed up, I guarantee that long distance trunks have filled up or dropped plenty of times without you being aware
Even if the long distance trunks did drop, how is that the fault of the OP's landline? After Hurricane Wilma, when cell phone towers were either down or overwhelmed or had no power, my landline was still working. A lot of my neighbors had to borrow my phone. I even gave my next door neighbor an old handset to use at his house - he had DSL and his landline worked, but he didn't have a plain old telephone.
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We both had DSL. Neither of us had "functional internet". POTS still worked, but my neighbor didn't realize he could use the phone line even if the internet didn't work.
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Most modern phones require external power now. Even the cordless phones will have a base station that needs to be plugged in. If you really want back up service in an outtage it might be handy to have an older phone in storage.
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I live in Chicago, in a GOOD neighborhood, and our options are cable and DSL. This "fiber" you speak of has not yet found its way to our particular back water.
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The problems aren't te
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I don't think "the last mile" means what you think it means.
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Generally speaking, when people are talking about limits on broadband in the US we are talking about later as applied to the former. There isn't even a beginning to a valid excuse for a Telco not having fiber on "the last
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Ummm... the great grand father post this entire conversation thread is under...
"Not everyone lives in a city. Even places that have "broadband" have pockets where DSL is the only option.
Just because you live in Seattle and have gigabit fiber doesn't mean the rest of the
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"Until you have actually worked in this industry, you should probably keep your opinions to yourself, as they are showing your ignorance."
Currently, I work at the major enterprise level
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It doesn't matter if there is no practical barrier to fiber. Profiteering ISPs are just as much a barrier as physical distance, since at the end of the day, you still don't have fiber to your home. And without major changes to the regulatory landscape, there isn't a damn thing you can do about it.
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The phone lines are also broadband in a sense. The DSL doesn't have to travel far, just up to the closest phone company station. So they don't have to stay within the narrower band used by voice but can use most of the bandwidth of the twisted pair. Thus it's "broad" band, or at least "broader" band relative to POTS. Of course you have to worry about other problems as well than just the band width, the old telephone wires have lots of junctions and branches even within a house and so it has to deal with