[HN Gopher] Splice a Fibre
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Splice a Fibre
It's interactive, try and splice one! Written in react, it's
moderately heavy and not entirely mobile optimised.
Author : matt-p
Score : 79 points
Date : 2025-12-27 11:57 UTC (11 hours ago)
(HTM) web link (react-networks-lib.rackout.net)
(TXT) w3m dump (react-networks-lib.rackout.net)
| zwnow wrote:
| We were splicing some fiberglass in job training a few years back
| and it was honestly pretty cool! The website is also really nice,
| I remember seeing the color codes on the splicing machine.
| Mesmerizing piece of technology.
| matt-p wrote:
| Definitely mesmerising the first time! We have ribbon fibre
| these days as well which is very cool too.
|
| Thank you :)
| ndom91 wrote:
| This would be a perfect plugin for Netbox!
| (https://github.com/netbox-community/netbox)
| Already__Taken wrote:
| I've always had stuff like this turned down by Netbox, they
| argue they want to model the logical topology as a source to
| trust, not the physicality, but then they model rack U
| placement. I'm always puzzled by their stance.
|
| Like you can't model 1 cat5 split into two 100mb terminations,
| patch panels are kinda of hack, I think you can now but forever
| you couldn't just swap a termination direction because
| logically why would you (but their UI gets messy when 44 are
| done A-B and the 45th B-A)
|
| Anyway that's thoughts as of maybe v2 or 3? Before the new UI
| when it was all jquery.
| wkat4242 wrote:
| > Like you can't model 1 cat5 split into two 100mb
| terminations
|
| Ugh I don't really blame them there, that's really a dirty
| hack. Sure I've done in a pinch but not for permanent stuff.
|
| I wouldn't call that professional network management. If you
| really wanna do it, just split the pairs over two patch ports
| IMO.
| bc569a80a344f9c wrote:
| One of the achievements in my career I'm lowkey proudest of
| is sneaking in the rewire of about 45,000 ports on a campus
| that were split pair after an explicit project to do so was
| shot down.
| matt-p wrote:
| Of course, but a splitter in a PON network or a WDM device
| are perhaps better examples of things that are hacky to
| model. Multi-fibre cables and splices are another. Netbox
| is great for some simple applications, and it's fantastic
| OSS, but in practice falls short for many use cases.
| wkat4242 wrote:
| I understand, my cabling OCD got a bit triggered, sorry
| :)
| toast0 wrote:
| > Ugh I don't really blame them there, that's really a
| dirty hack.
|
| I certainly wouldn't do it today, but using two pair for a
| connection designed for two pair isn't a dirty hack, it's
| as designed.
|
| Today, using 4 pair for 1G or more and a small switch on
| the host side to get more ports is probably a better plan.
| wkat4242 wrote:
| Oh I wasn't aware of this actually being an intended
| usecase. And yes like the other poster said, pairing it
| with a phone infrastructure was more common (in the days
| before these went all IP of course).
|
| It was a bit of my OCD being triggered as well. I love
| neat cabling at work (at home it is chaos funnily
| enough).
| Already__Taken wrote:
| Yeh it's awful, but all of our CCTV was wired like this
| through patch panels with 24v/48v power injectors. 2
| cameras a cable. So that's what I needed to document,
| because in reality I can't book scaffolding and change
| rooftop cameras for a documentation tool.
| pbh101 wrote:
| Any links to PRs or discussions?
| erinnh wrote:
| Theres many.
|
| Here is one Discussion/issue that is currently annoying me
| again.
|
| https://github.com/netbox-community/netbox/discussions/9515
| https://github.com/netbox-community/netbox/issues/20005
|
| Netbox is full of these kinds of things. Where people ask
| for stuff or even create PRs for it and the Maintainer of
| Netbox shoots it down because _reason_.
| dfc wrote:
| Netbox project used to go on and on about the philosophical
| justifications for not including n-type connections or
| different types of LMR. But the most recent release notes
| that I read had a blurb about all the new coax cable types
| they are supporting. I understand having limited time but
| instead of saying "no" they always had to make lofty
| philosophical arguments. It's weird.
| Already__Taken wrote:
| Honestly that's fine I'm just glad I'm not crazy.
| maartenh wrote:
| Nice! You might want to fix your GitHub link in the footer
| though, it 404's for me right now :)
| matt-p wrote:
| Thanks! Sorry, looks like I made the repo private at some point
| I'll take a look later but for now I've fixed the link.
| candiddevmike wrote:
| I was a fiber installer once upon a time in the 00s. A guy I
| worked with who was "the splicer" for our team and has years of
| experience using the little easy bake oven thing swore by going
| off the smell to know when it's "ready". Probably not the
| greatest thing for your health considering he did at least 10-12
| of these a day.
| Sesse__ wrote:
| Modern fiber splicers are fully automatic, so you don't need to
| smell :-) The only thing that's still mostly by hand is the
| cutting (mostly stripping away the various layers of
| insulation).
| duskwuff wrote:
| Modern fusion splicers are also shockingly cheap. You can get
| one for under $600.
| Sesse__ wrote:
| Yup, I have one from AliExpress :-) Only done ~50 splices
| or so, though, but works really well.
| dboreham wrote:
| Plus tariff.
| Hikikomori wrote:
| Even 20 years ago when i was learning they were automatic.
| bcrl wrote:
| The old manual tools were extremely slow. Modern fibre splicers
| mean that a dozen fibres can be spliced in maybe a bit more
| half an hour, although cable prep cam take a significant amount
| of time depending on the cable type, number of cables and
| splice closure. Even more if you're using a ribbon splicer that
| fuses 12 fibres per burn.
| dtgriscom wrote:
| Are fiber splices really only a 0.02dB drop? That only a 0.23%
| reduction in signal (if I have my math right). Impressive.
| matt-p wrote:
| That is probably the very best case scenario, but possible yes.
| Typically you'd accept anything less than 0.1dB.
| cycomanic wrote:
| I did my PhD on fibre lasers, 0.1 DB would have been
| considered a ver bad splice and I would have recut and
| respliced (if you have 1-10W in your cavity that 0.1 dB loss
| would risk burning and the fuse propagating through your
| cavity destroying everything in its path (as a side not look
| up Videos of fibre fuse, looks fascinating). In my experience
| 0.01-0.02 is much more typical than 0.1 dB loss.
| matt-p wrote:
| I'm speaking mainly within the context of telecom field
| splicing - the numbers I mentioned are typical for that
| application in my experience. You're only sending on the
| order of 5 mW down a fiber, so none of those high-power
| concerns apply. Obviously, different networks have
| different thresholds: if you're building a greenfield, low-
| latency long-haul route, you want to minimize loss and it's
| reasonable to spend the extra time and use higher-end
| equipment. For FTTH, with something like a 30 dB overall
| budget, nobody really cares whether a splice is 0.03 dB or
| 0.1 dB.
| Hikikomori wrote:
| You might accept a bad splice but you'd almost have to
| fuck it up on purpose with a decent automatic splicer.
| fsh wrote:
| Fiber splicers are marvels of technology. They align the fiber
| cores with sub-micrometer accuracy and produce just the right
| amount of heat and pressure to melt the ends together. They are
| also usually very rugged, fully automated, and surprisingly
| cheap (a few thousand euros). It is remarkable what is possible
| when the entire internet relies on a technology.
| sathackr wrote:
| The hardest thing about splicing fiber is not splicing fiber(at
| least not anymore)
|
| It's cable management and routing to keep things from kinking and
| breaking while accounting for cable flexing, thermal expansion,
| and unforseen circumstances like another company lashing their
| cables to yours for vertical support.
|
| All while maintaining future serviceability
| vasco wrote:
| And avoiding the NSA submarine taps!
| summa_tech wrote:
| Can always go splice some PCF or PMF if you like to feel
| appreciated for your splicing. I swear I'd rather splice 100 SM
| fibers than 1 PMF.
| gerdesj wrote:
| "like another company"
|
| What kind of org shares cabs? Monster!
|
| Your cab's environment should be pretty thermally stable. Your
| switches are probably venting to the hot isle through their
| front ports. Thermal expansion of glass and the sleeve is going
| to be negligible over a metre or so.
|
| Kinking is a possible issue. The minimum radius these days is
| quite tight. However, if you don't leave enough space inside
| the doors to allow for the terminations it will go horribly
| wrong. If you don't allow a gap for cable management between
| all switches and top and bottom, it might go wrong.
| richvos wrote:
| This looks really nifty, matt. I might be in the minority here,
| but would you consider making a similar model for PBX's? I'm
| having the hardest time visualizing all of the phone lines I have
| to deal with. This could be a really nice tool.
| kotaKat wrote:
| Are there a set of controls I'm missing? I'm confused on how to
| work with this.
| matt-p wrote:
| Click a unused fibre and drag it to an empty 'splice holder'
| then do the same on the other side. You can also use double tap
| on mobile I think.
|
| Sorry! In practice manual usage is normally very rare, these
| are typically auto generated!
| eru wrote:
| What am I supposed to do?
| Prcmaker wrote:
| In an old job I spliced a lot of fibre for our research, got the
| hang of it and got pretty proficient.
|
| My research shifted, and I start making sensors using fibre and
| similarly sized capillary tube. It all got cleaved, spliced to
| assemble, cleaved some more, spliced again, then polished to
| spec. Getting the he process down was a pain, but the results
| were super satisfying.
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(page generated 2025-12-27 23:00 UTC)