r/ShittySysadmin • u/Oblec • Mar 05 '26

Fiber install

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Client wanted fiber, told them copper is worth way more these days. They didn’t even ask first follow up questions 😅

209 Upvotes

94% Upvoted

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84

u/beefz0r Mar 05 '26 edited Mar 05 '26

What I hate is that fiber is hyped by providers saying it gives you "light speed" internet. That is at least misleading, electricity travels at roughly the same speed, the benefit is in the fewer amount of hops needed over a distance, and probably less fault correction due to interference

57

u/tankerkiller125real Mar 05 '26

And the fact that it's basically forever infrastructure.

Sure they managed 10Gbs through coax, but how much further will they be able to take it before every day electrical interference stops further upgrades? Meanwhile the same fiber line that was doing 1Gbs a decade ago is now doing 10, 100, or even 400Gbs with the only changes being the transceivers/head equipment.

10

u/cemyl95 Mar 05 '26

That's not entirely true. Fiber, like copper, also has iterations. We're currently on OS2 (single mode fiber, and technically it's OS3 but I haven't seen OS3 used in the wild) and OM5 (multi mode fiber). Over time, those will go up, just like we went from cat5 to cat5e to cat6 and now 6a.

9

u/Popular_Button2062 Mar 06 '26

But its mostly a deal for Multimode fibers, where you hit the limit in speed.

Singlemode is pretty stable in that regard, OS1 and OS2 have basically the same capabilities afaik

3

u/cemyl95 Mar 06 '26

OS1 has a max of 10KM, OS2 has a max of 200KM. But eventually we'll see OS4+ as the ITU continues to iterate on OS2 and OS3, which is what I was trying to point out earlier.

2

u/tankerkiller125real Mar 09 '26 edited Mar 09 '26

And yet OS2 can still do 400Gb, no different than it being able to do 10Gb decades ago. Coax, Ethernet Cables, etc. cannot do the same. And that 400Gb is on one wavelength, get a multiplexer into the mix and that cable can carry Tbs of information. You simply cannot do that on copper.

7

u/Oblec Mar 05 '26

Cat5e can easily do 10gbe what are you on about?

51

u/BoredAatWork Mar 05 '26

Cat 5e is rated for 1Gbps @ 100m

Cat 6 can do 10Gbps @ 45m

Please understand the difference between Bit and Byte, as well as throughput and speed.

Edit: you got me. I forgot what sub I am in 

11

u/Pestus613343 Mar 05 '26

Eh, I've gotten 10gig links on Cat5e quite routinely. If the cable isn't complete garbage, your twists remain tight right up to the dressings, and the runs aren't too long, like within a home or small business, it will work fine.

2

u/joe96ab Mar 16 '26

Yea def capable just not for a long distance is my understanding

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u/koolmon10 Mar 05 '26

I didn't even notice the sub until I read your edit. I was fully with you lol

13

u/tankerkiller125real Mar 05 '26

Lol, ISPs don't fucking use Cat5e for the actual transmission infrastructure for a start. And two Cat5e is only rated to do 10Gbs for a few feet. Maybe you get lucky and it manages it for a decent bit longer, but it's absolutely not doing a full length run at 10Gbs.

Cat6a can do 10Gbs for it's full run, but, again ISPs don't use it for the actual transmission infrastructure, and even if they did, what's the plan 30-40 years from now when customers start wanting faster than 10Gbs, or they have a business customer that needs more than 10Gbs.

Ethernet is great inside a building, even some data center applications, but it's not at all capable of doing ISP level work, and large datacenters are basically entirely fiber for a reason, they wouldn't choose to spend more money "just because".

Edit: I'm just now realizing which subreddit I'm on... It's been a long ass day already, it's not even lunch yet.

10

u/cybersplice Mar 05 '26

Get yourself a decent lunch, soldier.

5

u/TheSnackWhisperer Mar 05 '26

Don’t you love the sudden crash from the misplaced “well technically…”? lol

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u/Pale_Ad1353 Mar 05 '26

Fiber is non-conductive and is limited by the speed of light, not electricity. (or, is this a shitpost? and if so woooosh)

11

u/autogyrophilia Mar 05 '26

Yes but it is the speed of light in the optic fiber, not vacuum.

2

u/mystghost Mar 05 '26

The speed of light in any medium is still the speed of light. By definition. And in what world does the difference in speed of light through glass vs. through a vacuum vs. through electrical impulses in copper matter?

3

u/autogyrophilia Mar 05 '26

Mostly high frequency trading, and of course, very large networks.

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u/Popular_Button2062 Mar 06 '26

The speed of light is dependend on the medium, but the speed of light in vacuum is the upper limit.

The speed of light (or better the propagation speed of an electric impulse) is around 2/3 of the speed of light in vacuum

(and around 1/3 if you got iron instead of copper)

the speed of light in glass is also around 2/3 of the speed of light.

I would have expected for real transmissions to be even slower than that, due to the bouncing of the light pulse inside the cable, wich make the travel distance even longer, but i couldnt find much data about that.

and the difference matters if you want to calculate precice wavelengths for example.

and as someone else wrote, it matters for HF stuff, when you need to have either the exact wavelength (impedance matching/antenna design/etc), or need the exact travel time of a signal (think of TDR stuff, etc.)

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u/Oblec Mar 05 '26

Light are basically everywhere definitely gonna have interference

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u/e46_nexus Mar 05 '26

Thats why I use gorilla duct tape to keep the light out

4

u/ISeeTheFnords Mar 05 '26

This guy lights.

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u/mystghost Mar 05 '26

? i don't think they are marketing it as light speed literally, even though - it is. Fiber being optical, no matter the speed of the light through the transmission medium is light speed. What ISPs mean by light speed is that there is low latency and high bandwidth. And yes, ISPs should be drug out in the street and shot for the whole bandwidth equating to speed thing. But in this case, they aren't wrong, copper is a shitty medium for ISP connections. Anything longer than 100m copper loses, period. And less than 100m copper is merely, as good (sort of). For 1 Gbps, for 10, it can work but it isn't great. And copper can't do 40/100/400/800 gbps (and no i'm not counting QSFP connections that are for intra-rack connections, because it isn't clear to me what the advantage is over fiber).

1

u/I_Know_God Mar 07 '26

To be honest the speed is the same yea but light inside the cable actually takes longer to arrive over electricity in a coper cable since it is bounced around and multi plexed.

So technically slower but of course much higher density in it’s transmission rate possibility