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10mbps over 1km on a single pair of wires

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Re: 10mbps over 1km on a single pair of wires

#131

Post by dekhn »

netsharc wrote: post #88
geozimm wrote: post #84

All these things are related. Back in the 1990s I worked with others to develop DSL technologies (ADSL, HDSL, VDSL) for telcos. Why not fiber, some ask? oh, fiber materials may be sand, but installed fiber is sand, energy, and labor. Installation costs trump everything - use what you have for the physical medium. While we (PairGain) also made point-to-point private links, it was clear then, and even moreso now that m…

Al Gore never claimed that, btw, but he did recognize its importance and provided political support, even Vint Cerf said so: https://www.snopes.com/fact-check/internet-of-lies/

there is an entire multiverse fan fic where Al Gore won the presidential election and we're all living in a post-scarcity society.

Re: 10mbps over 1km on a single pair of wires

#132

Post by sethhochberg »

nousermane wrote: post #71
Youden wrote: post #55

Earlier quoted context omitted.

You linked unterminated single-mode fiber and a dual-fiber multi-mode media converter, you can't actually use these together. You need something more like this: - Terminated single-mode fiber: https://www.fs.com/products/74355.html?attribute=255&id=3029... - 2x SFP transceivers: https://www.fs.com/products/75335.html - 2x media converters (or NICs): https://www.fs.com/products/96396.html The price is over $200.

Wouldn't cost of burying that cable be like 50x of that anyway?

These solutions for things like IP-over-copper-pair are typically designed for situations where you already have the cable buried or strung on poles or whatever - so the choice isn't whether to lay new copper or lay new fiber at roughly equal expense, its really whether to use the existing copper or lay the new fiber at much greater expense

Re: 10mbps over 1km on a single pair of wires

#134

Post by jagger27 »

sethhochberg wrote: post #132
nousermane wrote: post #71

Earlier quoted context omitted.

Wouldn't cost of burying that cable be like 50x of that anyway?

These solutions for things like IP-over-copper-pair are typically designed for situations where you already have the cable buried or strung on poles or whatever - so the choice isn't whether to lay new copper or lay new fiber at roughly equal expense, its really whether to use the existing copper or lay the new fiber at much greater expense

Thank you, this wasn’t clicking for me until I read this. Of course there are countless places with a dead phone line hanging between them.

Re: 10mbps over 1km on a single pair of wires

#135

Post by repiret »

midasuni wrote: post #89
cm2187 wrote: post #87

Earlier quoted context omitted.

Fiber doesn’t conduct electricity, a wire does. I remember reading somewhere to be careful with running a wire over any long distance between two houses that are not connected to the grid with the same meter. Something to do with phase or different potential, can’t remember, but the point was it could fry your equipment. Fiber sounds a lot safer to me.

The biggest problem is lightning strikes hitting the cable. The phase wouldn’t matter - and even different earthing wouldn’t matter as long as you only connect any shield at one end. But fibre is so much more versatile if you’re running new cables (unless you want to run power)

Last summer the local cable company replaced all their cables in town in order to begin offering digital cable and internet service. I was flabbergasted that they they spent all that money on linemen but still ran coax rather than fiber. As far as I can tell talking to their linemen, its not even FTTN, just FTT-central-office.

Assuming its not run by morons, which I'll accept is a bit of a stretch for a cable company, there must be some other reason to not run fiber for new installations.

Re: 10mbps over 1km on a single pair of wires

#136

Post by Aloha »

willglynn wrote: post #102
aidenn0 wrote: post #91

Earlier quoted context omitted.

Magnetic coupling removes any issues with potentials, and if it's not AC at the same frequency as what's in the wall, the phase is irrelevant.

I'd like to add a few asterisks: Magnetic coupling removes issues with potentials _up to the dielectric breakdown voltage_. Ethernet magnetics are considered high potential components, and even the entry level options will isolate at least 1.5kV, but fault events often exceed that figure. Magnetic coupling removes issues with _common mode_ potentials. If the + and - side of a pair are both a thousand volts away from…

Inductive pickup (foreign voltage) from even fairly long runs (20kf +) of well maintained copper is usually much less less than half a volt, measuring either T-R, or T-G/R-G. It's supposed to be floating to ground - nothing on a twisted pair should be ground referenced, if you do have voltage to ground, you have a short.

If it was not floating, you'd get atmospherics, hum, and other issues that you saw in old fashioned ground return systems.

Indeed, measurement of voltage and continuity of T-G and R-G is a standard way to check for faulty cable

Re: 10mbps over 1km on a single pair of wires

#137

Post by yosheli123 »

geozimm wrote: post #84

All these things are related. Back in the 1990s I worked with others to develop DSL technologies (ADSL, HDSL, VDSL) for telcos. Why not fiber, some ask? oh, fiber materials may be sand, but installed fiber is sand, energy, and labor. Installation costs trump everything - use what you have for the physical medium. While we (PairGain) also made point-to-point private links, it was clear then, and even moreso now that m…

Awesome to have your input on this. I'd love to talk to you in person to learn more. Reach out at josh@botblox.io

Re: 10mbps over 1km on a single pair of wires

#138

Post by Aloha »

repiret wrote: post #135
midasuni wrote: post #89

Earlier quoted context omitted.

The biggest problem is lightning strikes hitting the cable. The phase wouldn’t matter - and even different earthing wouldn’t matter as long as you only connect any shield at one end. But fibre is so much more versatile if you’re running new cables (unless you want to run power)

Last summer the local cable company replaced all their cables in town in order to begin offering digital cable and internet service. I was flabbergasted that they they spent all that money on linemen but still ran coax rather than fiber. As far as I can tell talking to their linemen, its not even FTTN, just FTT-central-office. Assuming its not run by morons, which I'll accept is a bit of a stretch for a cable company…

Cost and Fragility.

You can push around 1GHz of bandwidth on the normal hardline-feed line with taps system cable uses, each node is designed to pass by a certain number of households.

Coax is.. cheap, forgiving, easy to terminate, and inexpensive to replace - Fiber is more expensive, unforgiving, and much harder to terminate.

Re: 10mbps over 1km on a single pair of wires

#139

Post by Aloha »

madaxe_again wrote: post #111
midasuni wrote: post #89

Earlier quoted context omitted.

The biggest problem is lightning strikes hitting the cable. The phase wouldn’t matter - and even different earthing wouldn’t matter as long as you only connect any shield at one end. But fibre is so much more versatile if you’re running new cables (unless you want to run power)

Then you just install a lightning arrestor on your comms circuit - I have a mast way up the hill to provide our connectivity here, and use one on the Ethernet line down to prevent issues (like a house fire) from a strike.

You have to assume a direct hit by lightening will fry your hardware, period, full stop - proper grounding and lightning protection however will mean that the hardware does not catch fire.

Re: 10mbps over 1km on a single pair of wires

#140

Post by Xeoncross »

netsharc wrote: post #88
geozimm wrote: post #84

All these things are related. Back in the 1990s I worked with others to develop DSL technologies (ADSL, HDSL, VDSL) for telcos. Why not fiber, some ask? oh, fiber materials may be sand, but installed fiber is sand, energy, and labor. Installation costs trump everything - use what you have for the physical medium. While we (PairGain) also made point-to-point private links, it was clear then, and even moreso now that m…

Al Gore never claimed that, btw, but he did recognize its importance and provided political support, even Vint Cerf said so: https://www.snopes.com/fact-check/internet-of-lies/

"During my service in the United States Congress, I took the initiative in creating the Internet"

Sounds like we're playing word games at this point.

Imagine that, a politician playing word games.

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