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Comment by hotpotamus | Hacker News Reader

It seems that single mode fiber is king for long distance cable runs now, nevermind that it can push gigabits. What kind of cable would this be and is it actually much cheaper? My impression is that most cost of cabling now is the labor to run it as opposed to the medium, but I'm a neophyte for sure.

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Basically just any CAT5e like twisted pair has worked for me up to 1km. 26AWG unshielded twisted pair basically, 100Ohm diff impedance. Cost of cabling is pennies IMO. Labor cost, who knows.

Optical can be quite expensive though these boards aren't exactly cheap (yet).

I've actually had to deal with fiber for the first time in my career recently and it was actually easier and cheaper than I imagined. I think my take on costs was about a decade out of date and things have gotten pretty affordable these days (for 1Gbps at long range at least). Probably all the fiber to the home providers have pushed the economies of scale on these things.

But here's sort of an example of what I'm talking about.

https://www.amazon.com/Gigabit-Ethernet-Converter-1000Base-L...

So the cost is pretty low if you wanted to terminate with these (these things aren't too loved in networking circles, but I can vouch that they do work), then the biggest difference is the cost of bulk cable - fiber vs copper. I assume the cost of labor to run it is essentially the same.

The main tradeoffs I see are that you can run power over catX cable (though probably not 1km?) but single mode fiber seems to be indefinitely able to upgrade bandwidth; I'm told that old installations from the 90's are still used and are pushing 100's of gigabits with newer optics attached to them.

Like I said, I'm fairly new to this having started a job where I have to talk to datacenter people about this sort of thing, so I'm learning a bit as I go.

Optical is not expensive anymore. It's 20 bucks for 10gbps transceivers. The cable is much cheaper than twisted pair. termination will take you no longer than a network cable.

The world is not the same as it was 15 years ago :)

A common use case for this is to use existing infrastructure like in an industrial setting. You can also provide power over a cable like this.

> It seems that single mode fiber is king for long distance cable runs now, nevermind that it can push gigabits.

Bandwidth isn't the only consideration: you can deliver power over copper:

* https://en.wikipedia.org/wiki/Power_over_Ethernet#PoDL

* https://www.ti.com.cn/cn/lit/an/snvaa25/snvaa25.pdf

Main reason POE is useful is that it lets you deliver power over existing wires. If you are running new wires, you can already do what you want.

They make plenty of fiber+power in single cable, because the fiber is unaffected by the power.

Running 1km of slow, expensive, single-pair cable to run low-data rate + power, vs fiber+power cable saves you essentially one connector. For very high cost - in money and loss of bandwidth.

Plus 10base-t1l is not common, so the price of equipment is high as well.

Fiber has the downside of being extremely vulnerable to mechanical damage or dirt and expensive on long runs. This here runs on virtually anything that's twisted-pair wire.

I wired my house with 62/125 fiber 22 years ago as a 1 km spool was only $250. I’m too lazy to look it up, but I suspect multimode fiber is cheaper than copper, and termination kits are cheap now.

I’m running 10G on single mode 100 ft jumpers to a few computers in the house and that’s cheap too. SFP are $35 but the NIC are more.

Yeah, multimode fiber seems to be the red headed step child of the networking world these days, but that's a good question about the cost of it vs copper. It's just plastic, right? It seems like a good option for high speed SOHO or perhaps within rack networking. But if I was running cable in my house today, I think I'd still go copper for PoE capability.

Yeah, POE is great. I have a 48 port Ubiquiti switch with POE AP and cameras. I ran duplex fiber and 2 pair of shielded CAT 5 to each room. For the downstairs rooms, those are through short runs of conduit to the basement, so I can poke whatever else through there, like the single mode jumpers. I should have run conduit upstairs, but I do have a 4" PVC running from basement to attic, so I could run single mode upstairs, but would require drilling and fishing.

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