[HN Gopher] ADSL works over wet string (2017)
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ADSL works over wet string (2017)
Author : fanf2
Score : 174 points
Date : 2024-05-17 07:24 UTC (15 hours ago)
(HTM) web link (www.revk.uk)
(TXT) w3m dump (www.revk.uk)
| entuno wrote:
| There's also a follow up post that goes into a little bit more
| technical detail:
|
| https://www.revk.uk/2017/12/please-upgrade-me-to-adsl-over-w...
| hcfman wrote:
| Great experiment!
| latexr wrote:
| > Don't dare touch the string though...
|
| Why not? Is it dangerous, ou would it just make it stop working?
| danielbln wrote:
| The voltages used are very low, so it's more about adding
| impedance I'd say.
| dghughes wrote:
| Literally and electrically impeding.
| Bene592 wrote:
| If it's also used as an analog phone line don't touch, if
| it's ringing you will get shocked
| ale42 wrote:
| I guess it will rather disconnect the ADSL ;-)
| planede wrote:
| Well of course, I assume that's what my ISP is using.
| Rinzler89 wrote:
| Telekom Germany?
| YeahThisIsMe wrote:
| Has to be, it would explain my experience.
| IntelMiner wrote:
| Could just as well be NBNco in Australia
| Rinzler89 wrote:
| Rogers in Canada?
| lytfyre wrote:
| I believe Rogers are running DOCSIS-over-Sewage, the
| competing cable standard.
| hi-v-rocknroll wrote:
| Nawh, they're using ATM over finches. Those squeaks and
| chirps you hear outside are actually your packets.
| bpye wrote:
| I'm surprised they didn't stick with the standard RFC
| 2549
|
| https://www.rfc-editor.org/rfc/rfc2549
| hi-v-rocknroll wrote:
| Latency and packet loss. And finches take less feed.
| fransje26 wrote:
| I don't mean to boast, but on a good day, I get up to 4Mbps
| with Telekom. Welcome to the world of tomorrow!
| owenphen wrote:
| is this just a bot reposting old content?
| vhcr wrote:
| Does it matter?
| yowzadave wrote:
| Almost certainly--judging by their submission timestamps, they
| appear to never sleep. I guess you can farm a lot of karma by
| just re-posting old popular posts.
| pja wrote:
| Tony Finch is a real person: https://dotat.at/social.html
|
| He used to be hostmaster@cam.ac.uk, amongst other things. Why
| he's farming internet points on HN I've no idea!
| jon_adler wrote:
| A small world. I checked out his site and discovered I worked
| with his wife. He's the Finch in Coleman Finch. Rachel is you
| are reading this, Hi! Hope you are well.
| rvnx wrote:
| There are bots on HackerNews, 3 kind of them:
|
| - Comments bots (like on other threads), usually to promote a
| crypto-thing.
|
| - Submissions bots to farm karma (likely one of them here).
|
| - Upvotes bots (taboo).
|
| Recent karma is necessary for upvoting other posts, as there is
| a system which makes you can't upvote if you didn't get upvoted
| yourself.
|
| If you can upvote some posts on HackerNews (as it would be on
| Reddit) you can help people make a lot of money, but again, you
| need recent karma.
| utensil4778 wrote:
| Is that why I see so many comments that are just a paragraph
| or two pulled directly from TFA with no commentary or even
| indication that it's a quote?
| fanf2 wrote:
| Not entirely a bot and not entirely old content.
|
| I've got a lot of good stuff in my link log https://dotat.at/:/
| so I thought it might be fun to share a few retro classics.
| There has been some good discussion, so it seems to be worth
| it.
| whalesalad wrote:
| My wife and I have been looking for a property out in the rural
| parts of Michigan. One of the homes we went to visit with our
| realtor had left out a laptop computer in order to test the
| internet. Damn thing has ADSL and gets 2.2mbps down lmao. I do
| not miss the ADSL days.
| Rinzler89 wrote:
| _> Damn thing has ADSL and gets 2.2mbps down lmao._
|
| Had they considered an infrastructure upgrade to carrier
| pigeons, cans on a string, or smoke signals?
| ElFitz wrote:
| I started calculating the bandwidth for a continuous stream
| of carrier pigeons carrying 256GB flash drives, at different
| frequencies.
|
| But the latency and loss rate would make it all worthless.
| Rinzler89 wrote:
| Latency definitely, but imagine pigeons carrying 8TB M.2
| PCIe Gen-5 sticks strapped to their backs. That's some
| crazy throughput rivaling most domestic internet
| connections.
| makr17 wrote:
| Never underestimate the bandwidth of a station wagon full
| of tapes hurtling down the highway.
|
| https://www.reddit.com/r/vintagecomputing/comments/9of84w
| /ne...
|
| Rings true for me. In my younger days I was "privileged"
| to catch an early morning flight to San Jose with a stack
| of tapes that I then drove to Palo Alto. All because a
| RAID array had gone kaput and tapes in a carry-on
| provided better bandwidth than the upstream from the
| office where our backups were.
| kevin_thibedeau wrote:
| My home _used_ to get 4 Mbps down until water got into the
| paper insulated trunk lines and became unusable. My new pair
| maxxed out at 2. So happy that all my broadband internet
| surcharges were spent on improving the customer experience.
| AngryData wrote:
| The Thumb area has been getting direct home fiber through a
| power company co-op. Been pretty great, I got mine like 6
| months ago.
|
| Before this we didn't even get DSL because the lines were so
| degraded.
| OnACoffeeBreak wrote:
| 100 Mbps Ethernet over barbed wire was demonstrated back in 1995.
| [0]
|
| "Only four properties really affect the performance of most
| digital transmission structures. The "big four" transmission-line
| properties are impedance, delay, high-frequency loss, and
| crosstalk." Dr Johnson then goes to describe these properties in
| barbed wire.
|
| 0: https://www.sigcon.com/Pubs/edn/SoGoodBarbedWire.htm
|
| P.S. Yes, this is the Dr. Howard Johnson of the famed "High-Speed
| Digital Design" book.
| mschuster91 wrote:
| And a hundred years before that, you had farmers running DIY
| phone setups over their barbed wire fences [1].
|
| [1] https://gizmodo.com/barbed-wire-fences-were-an-early-diy-
| tel...
| Scoundreller wrote:
| " Each house had its own distinctive ring--two short one
| long, for example--and it was considered impolite to listen
| in on another's call."
|
| https://en.m.wikipedia.org/wiki/Party_line_(telephony)
|
| A party line! Our cabin still has a grandfathered one with
| the distinctive ring. I think we pay 1/4 of the regular rate
| so we keep it despite everyone having a cell phone now.
|
| I don't think there's anyone else on the line.
|
| Got a funny spam call with a recording for some miracle
| septic tank treatment. It asked me to press 1 for more
| information and I can't do that on a rotary phone. Scammers
| don't understand their target market. (We also don't have
| septic system, just an outhouse.)
| jonhohle wrote:
| What's the baud rate on that setup like?
| davidw wrote:
| I recall reading about one of the last public ones to get
| replaced back in the late 80ies, somewhere remote in Idaho.
|
| Here we go - 1990: https://www.washingtonpost.com/archive/n
| ational/1990/07/13/p...
| Faaak wrote:
| I guess you can, but your phone sends impulsions instead of
| DTMF tones, that nobody understands anymore. I'm surprised
| you can dial out actually
| Teever wrote:
| I got a 'digital phone line' through the local cable
| company installed about a decade ago. I had it hooked up
| to a rotary phone and I was able to dial out just fine
| with it.
| tomxor wrote:
| > It asked me to press 1 for more information
|
| If you have absolute pitch, and have a friend with absolute
| pitch (and I mean absolute frequency really not pitch), and
| are both freaks who can sing perfect sine waves... you
| could sing the dual tone for number 1 (697 Hz + 1209 Hz).
|
| Since at this point we are talking about mutant alien
| phreaks, you should also be able to do overtone singing and
| squeeze out a 2 or a 3 column on your own which are 10%
| flat and sharp from the 2nd order harmonic of the first row
| 697 Hz.
|
| Happy phreaking
| coding123 wrote:
| That's how to get your internet to dry up.
| rnhmjoj wrote:
| Yeah, ADSL being so good at handling a crappy physical medium is
| both a blessing and a curse. If it weren't for these technologies
| we would have probably had to replace those rusty copper pairs
| decades ago for fiber optics. Instead the protocols continued to
| improve (ADSL2, ADSL2+, VDSL, VDSL2+, vectoring, supervector...)
| and allowed ISPs to provide usable network speeds without
| spending a cent on improving the infrastructure.
| elzbardico wrote:
| Copper thieves to the rescue!
|
| Due to them, most ISPs in big cities in Brazil are switching to
| fiber to the home.
| hocuspocus wrote:
| You still need to bring fiber relatively close to the building,
| so it's not exactly happening without spending a cent.
|
| Fun fact: Switzerland operates the only significant G.fast
| deployment in the world. The technology was such a flop that
| Huawei stopped making the hardware.
| mschuster91 wrote:
| > Fun fact: Switzerland operates the only significant G.fast
| deployment in the world.
|
| Nope. In Germany, M-net (Munich) and NetCologne operate
| massive g.fast networks, and if you don't want Huawei, go for
| Adtran's 516 lineup on the ISP side and AVM on the CPE side.
| tgpc wrote:
| Zyxel and Fast Networks are also good on the ISP side (Not
| sure Fast Networks is still a thing - website seems to be
| down - but I run one of their DSLAMs and am happy with it)
| IntelMiner wrote:
| What about FTTC in Australia?
| hocuspocus wrote:
| Has G.fast been deployed in significant numbers in
| Australia? I thought it was a few thousands subscribers
| only.
| xxpor wrote:
| CenturyLink/Lumen has been using G.fast for most new FTTH
| deployments since 2016. They still install fiber to the
| outside of the house though, it's mostly about avoiding
| needing the installer to mess with wiring in the walls of
| existing houses, and being able to reverse power the
| outside node, instead of needing an outlet outside.
| mbreese wrote:
| This is funny. About 10 years ago, I had bonded ADSL for my
| internet (yay sonic.net). The idea being that two lines bonded
| together would have twice as much bandwidth as a single line.
| Each line had a max rate of 20Mbps, so I had a max of 40Mbps
| combined. It worked pretty well initially, but over time it
| degraded horribly. Because you could see stats for each line
| independently, I could tell that one line was operating at
| ~18Mbps and the other was around 2 and there was a lot of error
| recovery going on. After much complaining, I found out that one
| line was degraded and somehow reacted to rain (water got in the
| trunk somehow). And no, AT&T wasn't going to fix the broken line.
|
| I chose to just use the single (good) line.
|
| So, yes, I can confirm this does work in the field... but with
| about as much practically as you'd expect.
| Scoundreller wrote:
| I'm always a bit amazed when _every_ home has 2 lines running
| to it, and probably 99% of those second lines never get used,
| but telcos figured it was worth it for those occasional 2nd
| lines /fax lines or redundancy instead of ever needing to run a
| 2nd pull.
|
| Is this just a North America thing or an everywhere thing?
| mordechai9000 wrote:
| You could always move a line to another pair if one went bad.
| Not sure if that was part of the motivation or just a happy
| coincidence.
| lm411 wrote:
| I'd guess that back in the 80's and 90's those 2nd lines were
| used a lot more than 1%. Nowadays I wonder if even 1% of a
| single line is used. ;)
| Stratoscope wrote:
| Only two? Around 1995 we had _four_ phone lines: home, home
| office, fax, and modem. There were only three physical pairs,
| so two of the lines (I think the voice lines) came off one
| physical pair with a frequency division splitter.
|
| Some time later I saw a Pacific Bell truck and crew trenching
| the street. (We had underground utilities.) I excitedly asked
| them, "Are you running fiber?" "No, just more copper."
|
| I guess they saw the demand for lots of copper lines per
| house and decided to meet it!
|
| The underground phone lines did lead to some excitement one
| time. Their water sealing wasn't very good, and after a heavy
| rain the line would get noisy and clicky. During one of these
| episodes, we got a loud knock on the door: "San Jose Police!
| Open up!"
|
| I ran to the door and asked what was going on. One of the
| officers said, "We got a 911 call from this address. The
| dispatcher couldn't hear anyone on the line, and no one
| answered when they called back. So we're required to come out
| and investigate the situation."
|
| I replied, "That's odd, neither of us called 911. Oh... I
| think I know what may have happened. Come in and I'll show
| you."
|
| We went to the kitchen and I put the wall phone (remember
| those?) on speaker and had the officers listen. It was
| clicking up a storm!
|
| Then I asked them if they remembered the old rotary phones
| (they did). I explained how the phone dial worked by breaking
| and making the circuit _N_ times for each digit you were
| dialing. And it must have been that in that flurry of clicks
| that the circuit was broken nine times, then once, then once
| again.
| sirtaj wrote:
| In India it was pretty common for phones put in semi-public
| locations to have a lock on the dial to stop people making
| outgoing calls. But if you were motivated enough, you could
| still dial out by tapping the number out on the switch
| hook.
| toast0 wrote:
| If you go everywhere, you'll rapidly find countries where
| landlines didn't get meaningful penetration outside of
| metropolita areas at all.
|
| But even in North America, I don't think every home had two
| pair all the way to the central office. They might not even
| all have two pair all the way to the crossbox [1]. It was not
| uncommon to order a 2nd phone line, and not be able to get
| it, because there weren't any available pairs on your pole.
| Especially if your neighborhood was established well before
| the explosion of the internet and fax in the mid to late 90s.
|
| [1] https://en.m.wikipedia.org/wiki/Serving_area_interface
| riffic wrote:
| the telcos used to pressurize cables in order to keep water out
| of it
|
| http://www.airtalk.com/newsletter5.html
| ComputerGuru wrote:
| Did you have to pay twice the base price for the bonded ADSL
| setup?
| dfox wrote:
| Another issue with DSL bonding is crosstalk, which is pretty
| bad in many cases of telco wiring.
|
| 10 years ago there was a huge amount of surplus Cisco 1700s
| with SHDSL line cards (apparently coming from Czech
| government's project to connect every school to internet in
| early 00's) and we had huge spool of flat phone cable that was
| left over from earlier project. So we had the bright idea to
| wrap ethernet trafic in AAL5, pass that over SHDSL and use that
| as an LAN for anime convention. Interesting observation from
| that it matters whether the cable is coiled or un-coiled. We
| built and tested the whole network in a lab (with coiled
| cables), it worked well, the G.991bis bonded links synced up at
| 6Mbps with two pairs and everything was good. We labeled
| everything and we built the exact same thing (including same
| cables) at the venue and the links will not go above 1.5Mbps
| and were frequently losing sync. Disabling the second bonded
| pair caused it to work reliably at 2Mbps. (Back then, we did
| not need that much of bandwidth, it was essentially for few
| SCCP phones, some IP tunelled serial ports and ssh)
|
| Well, next year we bought two boxes of Cat5 cable and switched
| to native ethernet (and today the backbone spans are 10G fiber,
| as it also carries video streams).
| mhandley wrote:
| I remember Van Jacobson saying in the early 90s that IP would
| work over two tin cans and a piece of wet string. For several
| years, I set this as a possible student project, partly as a
| joke, but it was had no takers for quite a few years. Then in
| 2009 a student finally took me up on the offer. The main things
| we learned were that the tin cans were a bad idea (undesirable
| resonances), and that you could either do on/off coding at the
| string's resonant frequency, or try to stay well away from the
| resonant frequency, but then the signal strength was very low but
| you could distinguish multiple frequencies so do more interesting
| coding. In the end the project was successful, but the student
| ran out of time before he could really investigate in great
| depth.
| jedberg wrote:
| I remember back around '98, there were a bunch of product that
| you could get that would turn the electrical wiring in your house
| into an ethernet network. You'd plug the thing in and then as
| long as the other end was on the same breaker, it would work
| great. I used it in my apartment to get network from one room to
| the other.
|
| This reminds me of that.
| stavros wrote:
| Powerline adapters? They're fairly popular nowadays too, I've
| got four of them in my house.
| tmountain wrote:
| Same... getting a decent connection too.
| stavros wrote:
| Yeah, I got some Devolo ones, they're pricy but they're
| bulletproof. I've never had to think about them once in the
| five years I've had them.
| wooptoo wrote:
| Actually serious question: Would this work as fallback tech in a
| war ridden zone? Not over wet string, but over something like
| reclaimed copper wire from whatever is around. Suppose laying
| fiber would be too risky and is too fragile, cannot be patched up
| in the field.
| I_Am_Nous wrote:
| Fiber can be patched, but it take a lot more than just twisting
| the ends together like you can with copper. Usually they have a
| portable fusion splicer in case of a fiber cut and can at the
| very least fuse a length of fiber on each end of the break so
| it can pass light again.
| svilen_dobrev wrote:
| ah i don't know. A 2023 (~cheap) car reverse camera for a
| videorecorder with (looking like) usb protocol on the wire
| between, does not work if cable is more than 5m. Or if it is
| another 5m cable (utp, ftp, 4x1mm, combination, whatever. Only
| _that_ initial one). Period.
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