I have fs.com armored cable installed for 10 years now. Different times and spools. It is all in perfect shape. They test all their cable. Something is almost certainly disintegrating your cable. If you have any spare old pvc pipe or something in the basement, hit it with a hammer and see if it is brittle (the hammer should bounce). If it is brittle, I would not hang out in the basement until you figure out what is going on.
One random guess other than gases of various sorts: If you have the lights on a lot, it's possible you have lighting that is not properly uv filtered somehow.
(It theoretically could be lots of heat/humidity vs certain types of cable jackets, but that would be obviously noticeable most of the time)
The fiber and even the armor itself looks fine in your pictures and I bet the error rate is zero. Outside of bending, i can't see how you could damage the fiber when the armor is in perfect shape. That armor will unravel if you really damaged it. The speed thing is not how fiber works. It's hard to get marginal link enough to generate retries that degrade your speed by 10%. Most of the time either you have full speed link, no link, or so many errors speed is zero. The optics almost always have rx/TX signal strength DDM you can look at
Also did you say you direct buried it in cement? If so it's not rated for that. Direct burial and concrete tight/safe are not the same thing at all, not the least of reasons being concrete is highly alkaline (ph12-13) when poured
Thanks HN folks for all the comments. To clarify a bit, the cables are pulled through PVC conduits under the flooring before being buried in cement. Currently the hypotheses for why the cable disintegrated so quickly is hydrolysis and paint solvents. Singapore is extremely humid but this doesn't explain why the exposed cabling on the other end is still healthy and not crumbly.
The second possibility is that I keep the leftover wall paints (Nippon Paint Vinilex 5000) in the same room and have noticed that much of the solvents have evaporated. It is possible that the solvents in the air might have caused the cable to fail in 3 years. It would explain why the other ends that aren't exposed to the air inside the bomb shelter aren't falling apart.
Some other learnings from this. Buried cabling should always be permanently fixed and attached to a patch panel instead of dangling in the open. That was the original plan but I figured it wouldn’t be an issue. I was wrong. Always measure exact length of buried fibre cabling as they aren’t meant to be stored in loops.
Military-grade just means it has a spec, now, I will admit having a spec is nice, very nice. but in general it says little about the actual quality of the item. And if the spec can't be found or there is no spec. Probably best to stay away, in those cases they are not even selling you the snake oil but the sound of it sloshing in the bottle.
Yeah if you see something labelling itself "MIL-SPEC", that's grade A snake oil bullshit.
That said military spec stuff is actually generally a good sign that something is of higher quality than random off the shelf garbage but only if you know there's a specific spec you want it to work with. And most of the time you aren't even necessarily looking for a MIL-STD (standard) but rather a MIL-PRF (performance rating/spec).
So like if something is "MIL-SPEC" run. But if you see say a spool of fiber that is "MIL-STD-1678 compliant" and more importantly "MIL-PRF-49291 compliant" and "MIL-PRF-85054 compliant", that's probably a really good sign that it'll do its job. The former PRF documenting perf requirements for the fiber itself and the latter PRF the cabling/sheath's corrosion and deterioration resistance.
It's the military so odds are it'll probably cost extra for that and it'll still kinda suck but it'll suck in exactly the way they promised.
Military grade afaict just implies the military ‘could’ use it, by that definition almost any company sells military grade products or services, except companies who explicitly would not sell to the military.
In the US, "military grade" is like "natural". There is no legally enforced meaning, so it means whatever the manufacturer says it means. Sometimes that's something real and of some value, but the majority of the time it's just a meaningless marketing buzzword.
the military often writes a spec and then refuses to buy anything that doesn't meet it. Most soldiers are not going to walmart to get supplies - even f walmart sells that type of thing.
I don’t disagree but it’s not hard to understand why people think “military grade” means it’s better. “Military grade” communicates tough/durable/stress tested to a lot of people. Veteran/patriot isn’t an indicator of build quality, even if it is also pandering to a certain sensibility.
A company can not sell a product to consumers cheaper than it can sell to the federal government, and the federal government contract normally comes first. A lot of the stuff you can buy (minus restricted items), it'll just cost you.
They can't sell the same thing but they can sell something slightly different. put a different type of paint on it and you can sell for different prices.
But shitload of vendors won't bother and just sell you a "military grade" or, even in non-english speaking countriess, say a "MIL-SPEC Daniel Defense AR-15". They won't list every spec in detail. And they make good AR-15s (but not cheap).
Anyone who thinks the triggers listed as MIL-SPEC from, say, Geissele here:
Guess what? Its screen never broke overnight like the one of my MacBook M1 Air did (the infamous "bendgate").
I can bend my LG Gram's screen and it's keeps working fine. I can let it drop. Friend who sold it to me stepped on it when he woke up once.
There's a very big difference between saying: "There are shady vendors" and saying "Military specs do not exists and it's impossible for consumers to buy items passing military specifications".
Yes, there are dishonest vendors.
Yes, military specs do exist.
And, yes, it's possible for consumers to buy products passing (and even surpassing) actual military specs.
If you buy a commercial product labelled "military grade", you are also buying snake oil.
"Military grade" is generally shit. It's built down to a price, manufactured the cheapest possible way, so they can get the lowest possible tender submitted. Bonus prize if the manufacturer is owned by either someone already in government, or with close ties to someone in government.
The only "military grade" devices I own are some woefully unsuccessful radios, which failed in the market because they were actually good - easy to use, reliable, and easy to repair - which made them about 5% more expensive than the cheapest option which was made by a company part-owned by the government and part-owned by someone who donates heavily to the Conservatives.
Looking at the pictures it looks like the fiber itself might be inside of that spiral metal conduit in the middle and the outside is just abrasion protection. There are way too many strands for that outside bit to be the fiber. It's obviously bad that the outside plastic disintegrated, but it looks like the buried cables might be fine.
I have a similar problem on my car where the 12v wiring is disintegrating like this because the manufacturer tried to switch to a more environmentally friendly wiring. Now the wire jackets turn to dust at the slightest touch or if they vibrate too much. I'm forever tracking down intermittent shorts in the wiring harness.
The metal coil will hold the actual fibre itself, yes - after a few more layers of protection. This is what is usually called “armoured” cable and is suitable for suspension and direct in ground. Dunno why he’s using it indoors.
Honestly, this writeup is… weird? Dude doesn’t know you can terminate fibre at home with like $50 of gear?
I had the fucking fox attack a freshly laid 500 meter line, literally the day before I was going to stuff it in conduit and bury it. Didn’t just break the fibre, she (I know this fox, well) chomped it into pieces, hauled on the exposed Kevlar, generally had a party.
Did I despair? Did I launch a baby complete with bathwater into the sun?
No. I bought a cleaver, some alcohol wipes, some stripping pliers and a whole bunch of mechanical terminators.
Needn’t have worried. Repaired it, outdoors, first attempt, in the rain, and have since buried it - no problems five months on.
Hey actually I didn't know! It's my very first time dealing with fibre networking so I just maxed out the supposed durability specs. I figured I'd rather go overkill than regret not having done so. Ironic I know.
Unfortunately I can't easily dig the cable out and bury it again in this case. I'll have to figure out how to pull a new cable using the existing cable through the PVC conduits as the cable shares a larger conduit with multiple other fibre and Ethernet cables. The whole project was orchestrated remotely in a different timezone with me giving the electricians instructions over WhatsApp photos and audio recordings, so that limited what I could realistically control onsite back then. Often the contractors would proceed with a do first ask questions later approach while I was still asleep. The networking project was holding up the entire home renovation so everything was learnt and planned in a short amount of time.
AFAIK fibre splicing and terminating tools are very expensive. Do point me in the right direction for the $50 tools and I could go get some and DIY.
> AFAIK fibre splicing and terminating tools are very expensive.
They're more like $600 expensive than $6000 expensive these days. For very low budget, you could go with a mechanical (aerobic) splice; it's more loss, less robust and takes up more space, but doesn't require a fusion splicer.
I wanted to reach you regarding your comment here: https://news.ycombinator.com/item?id=44547866 Would you be willing to maybe elaborate on the problems caused - I've planned to adopt Miro Sameks for an application?
DM me via my about me, if interested. Would be very thankful.
Back in my day the local telephone company used waxed lacing cable for that sort of thing[1]. These days it seems that polypropylene string is popular (search on "conduit pull string").
You basically want something that is slippery and will tend to not get stuck. I have used Dacron fishing line, but that is mostly because I had a bunch of it laying around.
Yes, the whole thing is built like bike brake cables, with a spirally metal support core, the goodies up the inside, and then a nylon braid and PVC jacket over the top.
I have issues with the PVC-jacketed cables under the bonnet of my nearly-30-year-old Landrover, where the plasticiser has been baked out of the insulation and they've gone brittle. Worst affected are the wires to the fuel injectors and the lambda sensors, presumably because the former are at the top of the engine and get reflected heat off the bonnet, and the latter because they're near the literally red-hot exhaust downpipes.
That's okay for an old vehicle that you'd expect to repair, though.
I've seen the same problem in three-year-old Toyotas, and that is Just Not On.
BMW and Toyota have famously used bio-derived insulation reported to be like catnip for rodents.
The bio-oil plasticizers also migrate out more quickly in thermal cycling than the old dead dinosaurs approach. Hilariously, when I asked my mechanic about getting an M5, he laughed and explained that the radiator components are known to turn brittle and crack after 5-6 years because of this.
(I don't envy automotive folks. The stuff they have to deal with is next level.)
There's no link to the data sheet of the actual cable, but, yeah, looks like this should not have happened in such a short timeframe unless there's something really funny going on in that room, like ambient temperatures above 50 degC.
Another thing that should not have happened is installing the cable in loops in this way: any 'building' or 'underground' type cable needs to be of the exact length required at the demarcation point, fastened properly to prevent movement and terminated on a proper patch panel (can be a one-port box-type thingy for small setups), from where you use regular patch cords to connect your equipment.
(Loops are definitely allowed though, but that use case is mostly for aerial fiber to enable repair splices, and there are some very specific bend-radius and strain relief requirements, which, again should be spelled out in the cable data sheet)
> any 'building' or 'underground' type cable needs to be of the exact length required at the demarcation point, fastened properly to prevent movement and terminated on a proper patch panel (can be a one-port box-type thingy for small setups)
How exact is exact? :-) I once had to reterminate some fiber that was cut and terminated to exact length, which means there was literally two centimeters from the wall to the connector. I literally had to squeeze the fiber splicer up against the wall to have a chance at splicing on new pigtails, but I had two mis-cuts and I was hosed. :-)
> Another thing that should not have happened is installing the cable in loops in this way: any 'building' or 'underground' type cable needs to be of the exact length required at the demarcation point...
This hasn't been my experience with fiber entrance cables terminated by ILECs, Spectrum, and Lumen. They typically leave a significant service loop bound to the cable ladder or backer board-- usually 15-20 feet.
Depends on the type of cable assembly. If it's fiber strands inside a soft-ish plastic jacket (and most of the cable is in fact in conduit), a service loop is fine, albeit a bit pointless for most repair scenarios. For armored cables (which are significantly stiffer), you only do these loops in situations where you expect to need to replace significant sections (think 'getting hit by a falling tree' or 'particularly aggressive rodents') and you have the space.
Both tree and rat took out my fiber so the loops are definitely useful. If your fiber goes through your whole house it's significantly less work to only have to reconnect one end instead of redoing the whole run.
Thanks, I really appreciate the SMEs commenting here. I'm learning a lot.
Definitely learnt it the hard way this time. You're right that buried cables should be exact in length and fastened to a patch panel. I'll probably look into better conduit design as well for the next time (in 15 years?). Having shared conduits means I would risk damaging other cables if I tried to pull a new cable through.
Good conduit and patch panel design is definitely key for a happy life. Leaving some extra space/capacity initially is also a good idea, especially since (unless you're covering truly great distances) there's not exactly a lot of innovation in the single mode fibre space: strands you put in today (even if it's 'the cheapest stuff your vendor sells most of', which is generally my philosophy for selecting cables) will still be viable a few years down the road.
Sharing/in-place-repurposing conduit is not something I'd recommend, but if you must, leave a few dummy cables (a.k.a. 'pieces of string') on the initial install...
From one of the photos, the cable spec "G657A2" is visible on the outside - and specs listed for that indicate it's "bending insensitive single-mode fibre", apparently it can tolerate 10 loops around 15mm mandrel. (Which does surprise me).
But yes, agreed, a lot of "Er... why would you do it like that?" bits.
Those 10 loops definitely only apply to the single mode fibre itself, not the entire assembly with armor and everything, because that's just... physically impossible.
Cables for direct burial only like to be bent once or twice, and then only gently. Anything else may very well break the armor (whether plastic or metal), after which all bets are off.
Still, for the outer jacket to become brittle to the extent described, something else is required, which may very well turn out to be "shoddy manufacturing"...
I'm not sure either. It's not an air tight bomb shelter and it's used like an average storeroom, storing stuff like winter jackets, suitcases and paint. I do use small amounts of Calcium Chloride based dessicants to keep the room dry.
Radon is a noble gas. It's not going to affect fiber or wiring... but yes, if you're going to spend much time down there, definitely a good idea to check for it.
Interseting - I have high radon (mitigeted in the house via a fan), if I burry fibre what will I need to do to get something that will work? I have an outbuilding that I want to give internet.
From the photos, it does not look like the fibers themselves are damaged. You should check the error rate on both sides. If it is 0, the not optimal values of your speedtest are not related to your fiber. If it is not 0, the more likely issues are in order: connectors to clean (buy a cleaning pen), bend radius somewhere, faulty optics, then the fiber. You can also pay a professional to run an OTDR on your fiber. It would show where the fiber is degraded.
Regarding the last few sentences about the speedtest, Fibre doesn’t degrade in a way that you get 30 to 40% line speed. DSL did that, fibre doesn’t.
Speedtests for 10G are complicated and will show low numbers because of all the different TCP parameters and schedulers. Sometimes because peering links of your ISP or the speedtest providers are saturated.
I’ve had this failure on soft-touch usb cables from the 2000’s, not related to movement, just in a box in room temperature storage they disintegrate like this. It was described to me as thermoplastic elastometer degradation but I’m not really satisfied with that vague of an answer. Main comment thread when I first jumped in to discuss it: https://news.ycombinator.com/item?id=28054090
I have a couple of USB cables from the 2000's like this, some of them original apple cables. But most are fine.
While some show brittleless, more plstics goes gooey and tarry - especially some ABS coating that makes the material more grippable,like computer mice or binoculars.
There are very survivable fiber cables designed for stage and A/V setups for instance, and even "real" military grade ones. But the common thin LZSH stuff is surprisingly resilient in my experience, so long as it didn't kink the OP would probably have been fine with a "standard" cable. In any case I would always try to place fiber in a place where it can be re-pulled.. conduit, tray, or a plenum.
I bought a big spool of 6 strand Corning stuff a long time ago for various projects, the cost and diameter don't increase much to add some protection lines even if you never imagine using them they can save you a re-pull if you bugger something up in construction.
The contractors were probably dubious of that resiliency given their lack of experience. I recently ran fibre in my house and have to say I was pleasantly surprised that fiber patch cables (unarmored) can survive a good pull through a duct.
They can survive a 500m pull (in 100m stages, or the friction is too high) in mud and rain, through active water line.
Honestly, fibre, even unarmoured with just a standard Kevlar & HDPE sleeve is hardy stuff. When I first started mucking around with it a few years ago I was like “don’t breathe on it too hard”, now I’m like “tie the fibre in a knot on the bullbar and pull it with the truck”.
> Honestly, fibre, even unarmoured with just a standard Kevlar & HDPE sleeve is hardy stuff.
To be fair, it also got a lot better in the last 20–30 years. In particular, we now have bend-insensitive fiber for the last mile (G.657.A1/G.657.A2) and in general, we just figured out how to make it more robust.
You can kink the shit out of fibre and it’s fine. Like, I’ve accidentally managed ~15mm diameter loops while pulling and then proceeded to yank on them. The Kevlar takes the brunt. Only time I broke a fibre was when it was me and two other guys pulling on it as hard as possible - and instead of moving it went “ping”.
Fs.com are a well regarded company. The OP should contact them and see if there's a recall on those cables or something. Sounds similar to what happened with some mains power cables sold by a hardware store in Australia.
I don't regard them very well personally... I bought a bunch of DAC cables from them, only to have them start emailing me under the guise of assigning me a "account manager"... I blocked their domain from my mail server and told them to never contact me again.
Is it too much to ask to just be able to buy things without being chased around by someone?
I have a Newegg business account (and maybe a few more for other pc stores, I'd have to check), but I literally never have them trying to get me to buy things. /shrug
Right, but sometimes your account manager's job is to manage a giant RMA as a result of their manufacturing department f'ing up. So while I am greatful she did a good job, I would have preferred to not need an account manager at all...
In theory I can pull a new cable through. But practically it might be tough due to the number of bends (shelter -> wall -> vent -> ceiling -> wall -> floor -> room). In the worst case scenario I can give it a try, but it's probably going to destroy the new fibre cable when I pull it through. For now the connection still works, so I am hoping it doesn't get to the point where I have to give that a try.
you can always try the plastic bag + vacuum cleaner trick - take a thin flexible rope, tie it to a small plastic bag, stuff the small plastic bag into the conduit, use a vacuum cleaner at the other end to suck the plastic bag & rope through. You can then use the rope to pull through new cable. If you make the rope twice the length of the conduit, you can keep it in there indefinitely to pull through new cable whenever you want.
I've seen dummy wires being put in when the conduit goes in.
Say initially you need 2 wires from A to B. That probably means there's plenty of room left. So you just put 4 more other wires in there. When the time comes you need to pull a new one, you pull in the new by pulling out the old
To anyone reading this and assuming it applies equally to electrical conduit, it does not, which is why the NEC specs a maximum of four 90 degree bends between pull points. You could probably manage five, as was described, but it is technically disallowed (again, for electrical wiring - the NEC doesn’t care about networking).
Bends ideally need pull boxes, but given the lack of pull boxes, you might be able to use fish tape where where fish rods / glow rods don't work, if you cannot get a pullstring / pull cable going.
I sympathise with burying cables that you think are for life, only to need to replace them later.
We ran fibre cables in the ceiling when constructing our house. I requested the electrician to shield the cables with some tubing, but he probably thought I was being extreme. We have 9 cables, 2 of them don't work, likely from being bent by mistake or something.
The wiring is intermixed with electrical and ethernet (for cameras) cables, making the process a bit tricky. At least for us we might only have to cut the ceiling boards in a few places to help guide the replacement cables.
9/10 times the problem is at the terminator - they can get yanked out of position if they are pulled rather than the sleeve. Snip off the pulled end of the suspect line with Kevlar shears and shine an OFF down the other end - and you’ll probably see laser. It’s then a surprisingly simple job to re-terminate with mechanical connectors.
Anyone in the US military that has bought 'military grade' Bates shoes and pulled them out of a locker after a year just to see the soles disintegrate can likely tell you the value of 'military grade'.
There's gotta be more to it than that. I've got a pair of dress shoes I wear maybe thee times a year at most, and I've had them for somewhere between ten and fifteen years, perhaps longer.
The soles (rubber because winter) are in perfect condition, and the leather isn't too bad either, though I've not really conditioned it enough and it's starting to show.
Both can be true. I have specifically heard that shoe glue needs to be repeatedly compressed to be maintained or it will disintegrate. Anecdotally as well, I had a pair of quality, lightly used, but old, hiking boots that had the sole completely separate after a day of heavy use. The runber sole completely detached from the leather shell inner shoe. The crazy thing was that BOTH boots failed within 20 minutes of each other.
I believe, he might have stored some solvent in the vicinity of the cable.
Anyway it won't affect the optical performance of the cables. It's just the loss of mechanical protection.
The disintegrating sheathing could be repaired by shrink tubing, which is more convenient than by wrapping it up in tape.
My friend also always runs multiple string lines through during construction. Later if a wire breaks or you want an additional cable or upgrade, you attach your new wire to a string and pull the string from the other end all the way through. If they had done this, they could have simply dragged a new fiber optic cable through.
PVC used in water pipes had some surprises, the lifespan there turned out to be less than optimistically expected when PVC pipes came to the market. 100 years might be hard to test for...
Is it a humidity problem? in our climate in the Med all kinds of plastic, pu and rubberised materials will just start cracking and flaking after a year or two.
...so it is a bit amusing to see "TPU Jacket Features Water, Abrasion Resistance" in the product description. PVC or PE would be far better and more common.
Be aware, depending on where you live and where the cable goes, PVC and HDPE outer jackets may not be allowed due to fire safety issues. But yes, neither of those are prone to the same degradation over time, so in many cases they will be a good choice.
> A main component of why I was in sheer horror was the fact that I had stupidly buried all of these cables under my cement flooring in PVC trunking from my shelter to all of the rooms in the flat.
This I don't quite get .. as I understand it "PVC trunking" is a type of cable channeling / ducting.
I do a lot of cable and pipe layout around houses, farms, workshops, worksites, etc. and it's routine to use pipes / ducting / channels to allow other cables to be threaded through after or to replace bad cables.
As much as cable deterioration sucks it should be a relief to have ducting to pull good through after the bad.
The electricians mentioned that in order to curve the cables along underneath the floor tiling they couldn't use metal trunking which would cause sharp angles, so they used PVC pipes to do curvy trunking for the fibre cables. I could theoretically pull a new cable through by ripping out the wall outlet if this cable actually fails. You can see it in my earlier homelab post. But due to the length of the trunking and the number of bends, I'm not too sure if I can safely drag a new fibre cable through.
But yeah, maybe it's not that bad after all. I hope it won't get to that point.
One of my love / hates is Australian parrots and cockatoos - fantastic birds, noisy as hell - and they can rip out and shred unprotected wiring from rural camera and sensor systems like winged can openers.
> due to the length of the trunking and the number of bends, I'm not too sure if I can safely drag a new fibre cable through.
I saw someone commented elsewhere about a plastic bag and a vacuum. Another option to keep in mind is a lubricant intended specifically for the task of pulling cable through a conduit.
In the olden days, when things like TVs and VCRs had cabinets made from polystyrene and PVC-jacketed power cables, you'd often find that if something had been put away with the mains lead coiled up on top, it then left a "scar" on the case. This is because the plasticiser in the PVC jacket attacked the polystyrene, leaving the mains lead fragile and brittle and a nasty gooey mess on the case that you couldn't fix.
That's why the leads are wrapped in a polythene bag.
When people started using polystyrene sheet insulation in houses (thankfully they no longer do this!) the cables running inside the walls were affected in the same way, with the PVC insulation rotting off as the plasticiser leached out and attacked the polystyrene. Of course there you had the added joy of having a potential electrical fire with a source of just-about-inextinguishable fuel, the polystyrene foam made of fuel and air.
I wonder if something similar has happened here, something's gotten onto the fibre jackets and pulled the plasticiser out?
Would that be this item? [1] The product description and SKU match.
It's not clear who "FS" is. A reseller? A manufacturer? They seem to be in Singapore. There's no excuse for the external plastic sheath disintegrating. They must have formulated the plastic wrong. The terms specify a 30 day warranty.
Here's a catalog of real mil-spec fiber optic cables.[2] This is overkill for home applications; you put these in a fighter jet.
In between are Telecom Industry Association compliant fiber optic cables. That's what telcos use. There are US manufacturers with real plants and addresses.
FS is a US company. They are a fairly reasonable option for third party networking equipment. We run a ton of their SPF+ transceivers in our racks, as they're significantly cheaper than OEM parts and indistinguishable in operation and we've had excellent support the handful of times we needed it over the years.
This looks like regular hydrolysis, same thing that happens to shoe soles after any number of years.
I don't think it's fair to make fun of the cable specifications, seems to me they held up just fine despite the jacket disintegrating. The article doesn't mention the error rate, but I wouldn't be surprised if it was still zero.
Many people believe running fibre between buildings, even in ducts, is safer than running copper because you get opto-isolation from lightning.
The second thing is that domestic buildings usually do not come with a consistent ground plane. I worked in a 1960s build purpose made for mainframes and we had ~48v floating between racks at either end of the building and had to do a shitload of work to reground the building, in the 90s (-we were decommissioning an IBM 3033 and deploying a secondhand cray1) the point being somehow, God knows how, prior rs232 serial wiring didn't care and the ground plane for the mainframe was fine at the time. Pre Ethernet this stuff maybe just passed code.
I suspect people who build their own home to some spec acquire these theories. Data comms? Not much reason tbh unless you're pushing a lot more data than normal.
> The second thing is that domestic buildings usually do not come with a consistent ground plane.
Ordinary unshielded copper Ethernet doesn’t care: it’s transformer-isolated at both ends. Shielded cable may object to carrying any substantial amount of current through the shield.
Anyway, there are a handful of good reasons to use fiber:
- Length. Copper is specced for 100m. Panduit will sell fancy copper cable that they pinky-swear works for Ethernet at 150m. Single mode fiber will work at silly long distances.
- High bandwidth. Copper will do 10Gbps. High speed specs exist, but there is approximately zero commercial availability of anything beyond 10G using copper at any appreciable distance. Fiber has no such problems.
IMO if you are running fiber anywhere that makes it awkward to replace (i.e. not just within a single room), use single mode. Multimode fiber has gone through ~5 revisions over the last few decades, and the earlier ones have very unimpressive bandwidth capabilities at any reasonable distance. Even the latest version, where truly heroic engineering has gone into reducing modal dispersion, relies on fancy multistrand cables for the faster Ethernet speeds. Single-mode fiber, meanwhile, continues to work very well and supports truly huge bandwidth at rather long distances, and even decades-old fiber supports the latest standards. And the transceivers for single-mode fiber are no longer much more expensive than multimode transceivers.
It's one of those "just because" moments. The idea was to future proof my home infra for a 25G NAS connection. Most ethernet connections tap out at 10G. While theoretically speaking Cat 8 cables can do 40G, hardware support for full 40G Cat 8 NICs is rare. Fibre is very very flexible with its potential bandwidth and SFP28 transceivers are relatively affordable (if you don't do what I did by using SMF. Home networks should only use MMF if the property isn't a mansion.)
I still prefer SMF over MMF. It also allows me to "move" where the city fiber comes in and patch it to another location without any active hardware. So I can for example move my router into another room.
10GbE rj45 (normal ethernet jack) spf modules tend to burn power and get extremely hot, like to the point of burning you if you touch it - the manual for my switch said to leave adjacent ports unoccupied if using one of those. The fiber ones run cool to the touch.
Also, not needing to rerun any cabling if we want to bump up speeds in the future, you just change the laser module on either end. These should be good to >100x current speeds. Not the case with copper.
The real problem here is that 10GBASE-T is ancient. The spec dates back to 2006! And worst of all: it only saw lukewarm adoption by the datacenter industry, so there hasn't really been a reason for manufacturers to refresh their lineups. This means that SFP+ transceiver you buy in 2026 might be using chips manufactured using a 20-year-old node. No wonder it is running hot!
2.5GBASE-T and 5GBASE-T are essentially using the same technology, but you don't hear anyone complaining about it running hot: hardware for this only recently started to become available due to consumer demand, so any hardware for that is being manufactured using more modern technology, which means a lower power use.
It's still going to consume more power than fiber, but a modern 10GBASE-T SFP+ transceiver should not be burning hot.
Fiber runs cool because it's operating well within the physical capacity of the channel. Copper needs an incredibly high signal to noise ratio to overcome the limitations of its medium. Copper will consume 5-10x more power than fiber for the same # of bits transmitted.
10G is looking to be the end for twisted-pair copper.
25GBASE-T and 40GBASE-T were standardized 10 years ago, but there are still basically zero products available with support for it. The datacenter market just wasn't interested and chose to use fiber and DAC instead. Worst of all: it requires Cat8 cables and is limited to 30 meters. This means it can't reuse existing cabling, and doesn't have the reach for many home applications - OPs blog post mentions the longest run in their apartment being 55 meters.
Combine that with the general death of wired networking for home & office use, and it is extremely unlikely the market of hardcore tech enthusiasts is big enough to warrant massive investments into developing some kind of 25G-over-Cat6-for-100m standard.
10G is pretty much the standard for high-end gear these days. This means any kind of future-proof setup needs to be prepared for a future upgrade to a fiber-based technology.
Ethernet can be run over copper or fiber cabling, it's not an alternative to fiber networking. Assuming you meant what's the advantage of fiber over copper: you can use faster speeds, longer distances less power on fiber plus it's not electrically coupled.
(speeds: 100 gig today, but faster speeds are coming.)
They get less hot (especially the network adapters on the ends of them), can go a lot further, can be a lot denser (including being able to carry things other than Ethernet in the same bundle), and are a lot more future-proof (unless the cable jacket literally crumbles at the slightest movement in a few years).
This is the most compelling reason (unless you really need the range of fiber) - 10GbE can be really power hungry. Each 10G switch port that is in use adds something like 1-5 watts to the power budget. 1 watt is reasonable but most switch hardware isn't nearly that efficient. That could mean 10 watts for every single link if you're using 5 watts at each end. Multiply that by several links and it starts to add up really quickly.
For me, it was for a nearly 100ft run that try as I may to get a good termination, I'd often find my Mac Studio and Ubiquiti EdgeSwitch struggle to negotiate at more than 5gbps. So I got a smaller switch upstairs, ran 10GbE to it, approximately 10ft, and then ran OM-3 fiber for the 100ft up into my attic, across my house and down into the garage. Rock solid at 10 Gbps.
FS.com is great for all kinds of fiber stuff… but curiously, nothing long-distance. I never really understood it; you can get a 40-channel DWDM setup (including tunable 100gig SFPs) just like nothing, but a drum of quite normal G24 loose tube cabling meant for outdoor use? Nope. You'll have to go elsewhere for that. And I guess that's also what happened here; the poster picked the best thing they had for the purpose, and it's just not that good.
I've also had problems with their pigtails also being weird, by the way (layers separating so that automated cutters can't stretch the pigtail properly). It's weird when everything else is so good—it's as if they only care about what's going on internal to a data center and you never need to do a splice. :-)
This is why should never-ever directly bury cables in the ground/walls/floor and ALWAYS use rigid PVC and/or flexible PVC tubes from site to site and pull the fiber or UTP cables through those tubes.
As an alternative if you are networking a single location and you don't mind seeing some finishing profiles on the walls (or want something easy in a pre-existing situation) you can also drill somewhere along the wall and feed the cables directly down to the floor or up the ceiling and cover them up.
But always, ALWAYS, make them easily accessible and easily removable.
Got plenty of experience to say no cable will survive a lifetime, and if you experience a problem without easy access you are fucked.
Coiled up high-speed fiber optic cables suffer data-abrasion due to centrifugal forces. Either reduce data speed or arrange those cables in straight lines with space-grade angle connectors.
Worse still, the loop-de-loops can make your packets dizzy which is an unpleasant experience for anyone doing a video call with you and makes games such as VR chat completely untenable.
If the point of a home lab is to learn useful lessons where your customers don't pay for your stupidity (or more politely: your learning journey) then this guy's next employer is definitely getting their money's worth.
But that reminds me of something: I spend money on hobbies, but I spend the absolute minimum amount of money possible on home IT research and learning. Fuck that noise: if my employer wants a lab, they can damn well pay for one.
I have fs.com armored cable installed for 10 years now. Different times and spools. It is all in perfect shape. They test all their cable. Something is almost certainly disintegrating your cable. If you have any spare old pvc pipe or something in the basement, hit it with a hammer and see if it is brittle (the hammer should bounce). If it is brittle, I would not hang out in the basement until you figure out what is going on.
One random guess other than gases of various sorts: If you have the lights on a lot, it's possible you have lighting that is not properly uv filtered somehow.
(It theoretically could be lots of heat/humidity vs certain types of cable jackets, but that would be obviously noticeable most of the time)
The fiber and even the armor itself looks fine in your pictures and I bet the error rate is zero. Outside of bending, i can't see how you could damage the fiber when the armor is in perfect shape. That armor will unravel if you really damaged it. The speed thing is not how fiber works. It's hard to get marginal link enough to generate retries that degrade your speed by 10%. Most of the time either you have full speed link, no link, or so many errors speed is zero. The optics almost always have rx/TX signal strength DDM you can look at
Also did you say you direct buried it in cement? If so it's not rated for that. Direct burial and concrete tight/safe are not the same thing at all, not the least of reasons being concrete is highly alkaline (ph12-13) when poured
Thanks HN folks for all the comments. To clarify a bit, the cables are pulled through PVC conduits under the flooring before being buried in cement. Currently the hypotheses for why the cable disintegrated so quickly is hydrolysis and paint solvents. Singapore is extremely humid but this doesn't explain why the exposed cabling on the other end is still healthy and not crumbly.
The second possibility is that I keep the leftover wall paints (Nippon Paint Vinilex 5000) in the same room and have noticed that much of the solvents have evaporated. It is possible that the solvents in the air might have caused the cable to fail in 3 years. It would explain why the other ends that aren't exposed to the air inside the bomb shelter aren't falling apart.
Some other learnings from this. Buried cabling should always be permanently fixed and attached to a patch panel instead of dangling in the open. That was the original plan but I figured it wouldn’t be an issue. I was wrong. Always measure exact length of buried fibre cabling as they aren’t meant to be stored in loops.
Oh, sry! Your comment came after I posted mine. I had similar experience with a bottle of organic thinner for paints.
If you buy a consumer product labeled "military grade" you are buying snake oil. And not just snake oil, incredibly over priced snake oil.
Military-grade just means it has a spec, now, I will admit having a spec is nice, very nice. but in general it says little about the actual quality of the item. And if the spec can't be found or there is no spec. Probably best to stay away, in those cases they are not even selling you the snake oil but the sound of it sloshing in the bottle.
There is no legal requirement for it to refer to MIL-SPEC. More often than not it is just pure marketing without any actual spec tied to it
Yeah if you see something labelling itself "MIL-SPEC", that's grade A snake oil bullshit.
That said military spec stuff is actually generally a good sign that something is of higher quality than random off the shelf garbage but only if you know there's a specific spec you want it to work with. And most of the time you aren't even necessarily looking for a MIL-STD (standard) but rather a MIL-PRF (performance rating/spec).
So like if something is "MIL-SPEC" run. But if you see say a spool of fiber that is "MIL-STD-1678 compliant" and more importantly "MIL-PRF-49291 compliant" and "MIL-PRF-85054 compliant", that's probably a really good sign that it'll do its job. The former PRF documenting perf requirements for the fiber itself and the latter PRF the cabling/sheath's corrosion and deterioration resistance.
It's the military so odds are it'll probably cost extra for that and it'll still kinda suck but it'll suck in exactly the way they promised.
TIL:
* https://www.navsea.navy.mil/Home/Warfare-Centers/NSWC-Dahlgr...
* https://landandmaritimeapps.dla.mil/programs/MilSpec/ListDoc...
Military grade afaict just implies the military ‘could’ use it, by that definition almost any company sells military grade products or services, except companies who explicitly would not sell to the military.
In the US, "military grade" is like "natural". There is no legally enforced meaning, so it means whatever the manufacturer says it means. Sometimes that's something real and of some value, but the majority of the time it's just a meaningless marketing buzzword.
the military often writes a spec and then refuses to buy anything that doesn't meet it. Most soldiers are not going to walmart to get supplies - even f walmart sells that type of thing.
I’m not talking about what the military could or would use, I’m talking about what it takes for something to be called military grade.
Exactly. It's a very successful marketing play on MIL-SPEC:
https://en.wikipedia.org/wiki/United_States_Military_Standar...
https://en.wikipedia.org/wiki/Military_grade
Basically same with any company with "Patriot" or "Veteran" in the name.
It's just a weak pander to people's weak egos. Freedumb, if you will.
I’m waiting for “Titanium Sourdough” optical fibres myself.
Well those materials are verifiable at least.
Tactical everything!
I don’t disagree but it’s not hard to understand why people think “military grade” means it’s better. “Military grade” communicates tough/durable/stress tested to a lot of people. Veteran/patriot isn’t an indicator of build quality, even if it is also pandering to a certain sensibility.
Not really if it is owned by Veterans. There are many veteran owned businesses and I see nothing wrong with it.
What if it's Military Grade Snake Oil?
Military grade: mass produced by the lowest bidder
I only use handmade artisanal networking equipment.
Well, not mass produced enough.
Common mass produced products manufacturers have incentives to not mess-up too badly: recalls or warranties on such scales are a nightmare.
With military contracts, its a paid maintenance opportunity.
There are plenty of things where mil spec is extremely strict and high quality. They wont be sold to consumers as they are priced accordingly
A company can not sell a product to consumers cheaper than it can sell to the federal government, and the federal government contract normally comes first. A lot of the stuff you can buy (minus restricted items), it'll just cost you.
They can't sell the same thing but they can sell something slightly different. put a different type of paint on it and you can sell for different prices.
"Military-grade" has a very specific meaning: it's at least 10x overpriced and painted black.
I personally look for the 1,000x overpriced space marine spec so I can get it in white.
Why black? Shouldn’t it be camouflage?
Drop it in some mud
But shitload of vendors won't bother and just sell you a "military grade" or, even in non-english speaking countriess, say a "MIL-SPEC Daniel Defense AR-15". They won't list every spec in detail. And they make good AR-15s (but not cheap).
Anyone who thinks the triggers listed as MIL-SPEC from, say, Geissele here:
https://geissele.com/triggers.html
aren't totally fine is out of his mind. They're amazing triggers, widely used and loved.
And they don't say which specs its passing (at least not on the main page): it's just MIL-SPEC.
As a sidenote my very best laptop passes https://en.wikipedia.org/wiki/MIL-STD-810 but most people will just say it's "military grade" or "MIL-SPEC".
Guess what? Its screen never broke overnight like the one of my MacBook M1 Air did (the infamous "bendgate").
I can bend my LG Gram's screen and it's keeps working fine. I can let it drop. Friend who sold it to me stepped on it when he woke up once.
There's a very big difference between saying: "There are shady vendors" and saying "Military specs do not exists and it's impossible for consumers to buy items passing military specifications".
Yes, there are dishonest vendors.
Yes, military specs do exist.
And, yes, it's possible for consumers to buy products passing (and even surpassing) actual military specs.
If you buy a commercial product labelled "military grade", you are also buying snake oil.
"Military grade" is generally shit. It's built down to a price, manufactured the cheapest possible way, so they can get the lowest possible tender submitted. Bonus prize if the manufacturer is owned by either someone already in government, or with close ties to someone in government.
The only "military grade" devices I own are some woefully unsuccessful radios, which failed in the market because they were actually good - easy to use, reliable, and easy to repair - which made them about 5% more expensive than the cheapest option which was made by a company part-owned by the government and part-owned by someone who donates heavily to the Conservatives.
Looking at the pictures it looks like the fiber itself might be inside of that spiral metal conduit in the middle and the outside is just abrasion protection. There are way too many strands for that outside bit to be the fiber. It's obviously bad that the outside plastic disintegrated, but it looks like the buried cables might be fine.
I have a similar problem on my car where the 12v wiring is disintegrating like this because the manufacturer tried to switch to a more environmentally friendly wiring. Now the wire jackets turn to dust at the slightest touch or if they vibrate too much. I'm forever tracking down intermittent shorts in the wiring harness.
The metal coil will hold the actual fibre itself, yes - after a few more layers of protection. This is what is usually called “armoured” cable and is suitable for suspension and direct in ground. Dunno why he’s using it indoors.
Honestly, this writeup is… weird? Dude doesn’t know you can terminate fibre at home with like $50 of gear?
I had the fucking fox attack a freshly laid 500 meter line, literally the day before I was going to stuff it in conduit and bury it. Didn’t just break the fibre, she (I know this fox, well) chomped it into pieces, hauled on the exposed Kevlar, generally had a party.
Did I despair? Did I launch a baby complete with bathwater into the sun?
No. I bought a cleaver, some alcohol wipes, some stripping pliers and a whole bunch of mechanical terminators.
Needn’t have worried. Repaired it, outdoors, first attempt, in the rain, and have since buried it - no problems five months on.
Hey actually I didn't know! It's my very first time dealing with fibre networking so I just maxed out the supposed durability specs. I figured I'd rather go overkill than regret not having done so. Ironic I know.
Unfortunately I can't easily dig the cable out and bury it again in this case. I'll have to figure out how to pull a new cable using the existing cable through the PVC conduits as the cable shares a larger conduit with multiple other fibre and Ethernet cables. The whole project was orchestrated remotely in a different timezone with me giving the electricians instructions over WhatsApp photos and audio recordings, so that limited what I could realistically control onsite back then. Often the contractors would proceed with a do first ask questions later approach while I was still asleep. The networking project was holding up the entire home renovation so everything was learnt and planned in a short amount of time.
AFAIK fibre splicing and terminating tools are very expensive. Do point me in the right direction for the $50 tools and I could go get some and DIY.
> AFAIK fibre splicing and terminating tools are very expensive.
They're more like $600 expensive than $6000 expensive these days. For very low budget, you could go with a mechanical (aerobic) splice; it's more loss, less robust and takes up more space, but doesn't require a fusion splicer.
If you want to pull another cable:
- secure a string to the old cable
- pull the cable out the other end, pulling the string through
- secure the string to the new cable
- pull the string out the other end, pulling the new cable into position
Pull a string alongside the new cable, too, and tie it off on both ends. Always leave a pull string in the conduit.
> a string
At this point, multiple. Just in case.
You forgot to also tie another piece of string to the new cable so that you pull the new cable AND this other bit of string through.
This gives you a piece of string in the conduit run to be able to pull through the next thing days/weeks/years later.
Excuse me to hijack this comment adinisom.
I wanted to reach you regarding your comment here: https://news.ycombinator.com/item?id=44547866 Would you be willing to maybe elaborate on the problems caused - I've planned to adopt Miro Sameks for an application? DM me via my about me, if interested. Would be very thankful.
> [...] a string [...]
Does someone have a recommendation for a specific material the string should be made of?
The sell pulling string in the electrical section of the hardware store.
Back in my day the local telephone company used waxed lacing cable for that sort of thing[1]. These days it seems that polypropylene string is popular (search on "conduit pull string").
You basically want something that is slippery and will tend to not get stuck. I have used Dacron fishing line, but that is mostly because I had a bunch of it laying around.
[1] https://en.wikipedia.org/wiki/Cable_lacing
They also make bottles of cable pulling lubricant for this purpose.
AKA boy butter [0].
0: http://www.electricalslang.com/Slang/boy%20butter
Yes, the whole thing is built like bike brake cables, with a spirally metal support core, the goodies up the inside, and then a nylon braid and PVC jacket over the top.
I have issues with the PVC-jacketed cables under the bonnet of my nearly-30-year-old Landrover, where the plasticiser has been baked out of the insulation and they've gone brittle. Worst affected are the wires to the fuel injectors and the lambda sensors, presumably because the former are at the top of the engine and get reflected heat off the bonnet, and the latter because they're near the literally red-hot exhaust downpipes.
That's okay for an old vehicle that you'd expect to repair, though.
I've seen the same problem in three-year-old Toyotas, and that is Just Not On.
Your car wouldn’t happen to be a Volvo would it?
Mini Cooper. From what I've heard it's a BMW thing.
BMW and Toyota have famously used bio-derived insulation reported to be like catnip for rodents.
The bio-oil plasticizers also migrate out more quickly in thermal cycling than the old dead dinosaurs approach. Hilariously, when I asked my mechanic about getting an M5, he laughed and explained that the radiator components are known to turn brittle and crack after 5-6 years because of this.
(I don't envy automotive folks. The stuff they have to deal with is next level.)
1990s Mercedes would be my guess.
The outside strands are kevlar. The fibers are inside the armored core often inside another jacket.
There's no link to the data sheet of the actual cable, but, yeah, looks like this should not have happened in such a short timeframe unless there's something really funny going on in that room, like ambient temperatures above 50 degC.
Another thing that should not have happened is installing the cable in loops in this way: any 'building' or 'underground' type cable needs to be of the exact length required at the demarcation point, fastened properly to prevent movement and terminated on a proper patch panel (can be a one-port box-type thingy for small setups), from where you use regular patch cords to connect your equipment.
(Loops are definitely allowed though, but that use case is mostly for aerial fiber to enable repair splices, and there are some very specific bend-radius and strain relief requirements, which, again should be spelled out in the cable data sheet)
> any 'building' or 'underground' type cable needs to be of the exact length required at the demarcation point, fastened properly to prevent movement and terminated on a proper patch panel (can be a one-port box-type thingy for small setups)
How exact is exact? :-) I once had to reterminate some fiber that was cut and terminated to exact length, which means there was literally two centimeters from the wall to the connector. I literally had to squeeze the fiber splicer up against the wall to have a chance at splicing on new pigtails, but I had two mis-cuts and I was hosed. :-)
> Another thing that should not have happened is installing the cable in loops in this way: any 'building' or 'underground' type cable needs to be of the exact length required at the demarcation point...
This hasn't been my experience with fiber entrance cables terminated by ILECs, Spectrum, and Lumen. They typically leave a significant service loop bound to the cable ladder or backer board-- usually 15-20 feet.
I have a > 75ft service loop on a 48-count underground burial fiber from the street.
Depends on the type of cable assembly. If it's fiber strands inside a soft-ish plastic jacket (and most of the cable is in fact in conduit), a service loop is fine, albeit a bit pointless for most repair scenarios. For armored cables (which are significantly stiffer), you only do these loops in situations where you expect to need to replace significant sections (think 'getting hit by a falling tree' or 'particularly aggressive rodents') and you have the space.
Both tree and rat took out my fiber so the loops are definitely useful. If your fiber goes through your whole house it's significantly less work to only have to reconnect one end instead of redoing the whole run.
Thanks, I really appreciate the SMEs commenting here. I'm learning a lot.
Definitely learnt it the hard way this time. You're right that buried cables should be exact in length and fastened to a patch panel. I'll probably look into better conduit design as well for the next time (in 15 years?). Having shared conduits means I would risk damaging other cables if I tried to pull a new cable through.
Good conduit and patch panel design is definitely key for a happy life. Leaving some extra space/capacity initially is also a good idea, especially since (unless you're covering truly great distances) there's not exactly a lot of innovation in the single mode fibre space: strands you put in today (even if it's 'the cheapest stuff your vendor sells most of', which is generally my philosophy for selecting cables) will still be viable a few years down the road.
Sharing/in-place-repurposing conduit is not something I'd recommend, but if you must, leave a few dummy cables (a.k.a. 'pieces of string') on the initial install...
From one of the photos, the cable spec "G657A2" is visible on the outside - and specs listed for that indicate it's "bending insensitive single-mode fibre", apparently it can tolerate 10 loops around 15mm mandrel. (Which does surprise me).
But yes, agreed, a lot of "Er... why would you do it like that?" bits.
Those 10 loops definitely only apply to the single mode fibre itself, not the entire assembly with armor and everything, because that's just... physically impossible.
Cables for direct burial only like to be bent once or twice, and then only gently. Anything else may very well break the armor (whether plastic or metal), after which all bets are off.
Still, for the outer jacket to become brittle to the extent described, something else is required, which may very well turn out to be "shoddy manufacturing"...
That seems incredibly fast for plastic to degrade like that. I wonder if you could have something generating ozone in there.
I'm not sure either. It's not an air tight bomb shelter and it's used like an average storeroom, storing stuff like winter jackets, suitcases and paint. I do use small amounts of Calcium Chloride based dessicants to keep the room dry.
Have you checked for Radon?
Radon and its progenitors won't produce nearly enough radiation to damage plastics like that at naturally occurring levels.
Water based or solvent based paint?
Should be solvent based.
If it's underground at all, check for radon.
Radon is a noble gas. It's not going to affect fiber or wiring... but yes, if you're going to spend much time down there, definitely a good idea to check for it.
Radon is radioactive. The alpha particles it emits can break down polymers and degrade plastics.
Interseting - I have high radon (mitigeted in the house via a fan), if I burry fibre what will I need to do to get something that will work? I have an outbuilding that I want to give internet.
No, radiation from radon at naturally occurring levels won't cause any damage to plastics.
My first thought exactly. I know someone who inadvertently melted a ton of stuff with overuse of an ozone generator, similar kind of effect
From the photos, it does not look like the fibers themselves are damaged. You should check the error rate on both sides. If it is 0, the not optimal values of your speedtest are not related to your fiber. If it is not 0, the more likely issues are in order: connectors to clean (buy a cleaning pen), bend radius somewhere, faulty optics, then the fiber. You can also pay a professional to run an OTDR on your fiber. It would show where the fiber is degraded.
Regarding the last few sentences about the speedtest, Fibre doesn’t degrade in a way that you get 30 to 40% line speed. DSL did that, fibre doesn’t.
Speedtests for 10G are complicated and will show low numbers because of all the different TCP parameters and schedulers. Sometimes because peering links of your ISP or the speedtest providers are saturated.
When I had 5Gbs fiber with a UDM I could never get it to speed test close to 5Gbps.
My internet network would would test at theoretical limits with proper iperf2 settings. I tried using public iperf servers but wasn't successful.
I’ve had this failure on soft-touch usb cables from the 2000’s, not related to movement, just in a box in room temperature storage they disintegrate like this. It was described to me as thermoplastic elastometer degradation but I’m not really satisfied with that vague of an answer. Main comment thread when I first jumped in to discuss it: https://news.ycombinator.com/item?id=28054090
I have a couple of USB cables from the 2000's like this, some of them original apple cables. But most are fine.
While some show brittleless, more plstics goes gooey and tarry - especially some ABS coating that makes the material more grippable,like computer mice or binoculars.
There are very survivable fiber cables designed for stage and A/V setups for instance, and even "real" military grade ones. But the common thin LZSH stuff is surprisingly resilient in my experience, so long as it didn't kink the OP would probably have been fine with a "standard" cable. In any case I would always try to place fiber in a place where it can be re-pulled.. conduit, tray, or a plenum.
I bought a big spool of 6 strand Corning stuff a long time ago for various projects, the cost and diameter don't increase much to add some protection lines even if you never imagine using them they can save you a re-pull if you bugger something up in construction.
The contractors were probably dubious of that resiliency given their lack of experience. I recently ran fibre in my house and have to say I was pleasantly surprised that fiber patch cables (unarmored) can survive a good pull through a duct.
They can survive a 500m pull (in 100m stages, or the friction is too high) in mud and rain, through active water line.
Honestly, fibre, even unarmoured with just a standard Kevlar & HDPE sleeve is hardy stuff. When I first started mucking around with it a few years ago I was like “don’t breathe on it too hard”, now I’m like “tie the fibre in a knot on the bullbar and pull it with the truck”.
> Honestly, fibre, even unarmoured with just a standard Kevlar & HDPE sleeve is hardy stuff.
To be fair, it also got a lot better in the last 20–30 years. In particular, we now have bend-insensitive fiber for the last mile (G.657.A1/G.657.A2) and in general, we just figured out how to make it more robust.
You can kink the shit out of fibre and it’s fine. Like, I’ve accidentally managed ~15mm diameter loops while pulling and then proceeded to yank on them. The Kevlar takes the brunt. Only time I broke a fibre was when it was me and two other guys pulling on it as hard as possible - and instead of moving it went “ping”.
Fs.com are a well regarded company. The OP should contact them and see if there's a recall on those cables or something. Sounds similar to what happened with some mains power cables sold by a hardware store in Australia.
I don't regard them very well personally... I bought a bunch of DAC cables from them, only to have them start emailing me under the guise of assigning me a "account manager"... I blocked their domain from my mail server and told them to never contact me again.
They offer to provide you with personalized service and you block them? What do you do when you walk into a high end watch or clothing store?
FS provides account managers and they are very useful if you are working on a project as they can guide you and help you.
Is it too much to ask to just be able to buy things without being chased around by someone?
I have a Newegg business account (and maybe a few more for other pc stores, I'd have to check), but I literally never have them trying to get me to buy things. /shrug
Right, but sometimes your account manager's job is to manage a giant RMA as a result of their manufacturing department f'ing up. So while I am greatful she did a good job, I would have preferred to not need an account manager at all...
Buried under cement/concrete. A good reminder of the benefits of planning to install some conduit.
The article mentions PVC trunking, which I take to mean conduit.
Then why the drama in the article ? Just pull another one through.
Came to the thread to see if anyone else had mentioned conduit.
It's cheap as chips and saves you a lot of future brick cutting or concrete breaking
I do have PVC conduits under the flooring. You can see the photos here: https://alienchow.dev/post/homelab1/
In theory I can pull a new cable through. But practically it might be tough due to the number of bends (shelter -> wall -> vent -> ceiling -> wall -> floor -> room). In the worst case scenario I can give it a try, but it's probably going to destroy the new fibre cable when I pull it through. For now the connection still works, so I am hoping it doesn't get to the point where I have to give that a try.
you can always try the plastic bag + vacuum cleaner trick - take a thin flexible rope, tie it to a small plastic bag, stuff the small plastic bag into the conduit, use a vacuum cleaner at the other end to suck the plastic bag & rope through. You can then use the rope to pull through new cable. If you make the rope twice the length of the conduit, you can keep it in there indefinitely to pull through new cable whenever you want.
This is an unreasonably effective way of running cables. The first time I used it it felt like magic with how quick and painless it was.
Fair enough! I had a cursory search in the post for mention of conduit and couldn't see anything obvious so wasn't sure.
AFAIK fibre cable should be pretty flexible, though not a massive fan of tension.
From memory bends shouldn't be less than 5cm radius or thereabouts so it depends on your conduit size!
Nice post btw, appreciate the detailed planning involved.
I've seen dummy wires being put in when the conduit goes in.
Say initially you need 2 wires from A to B. That probably means there's plenty of room left. So you just put 4 more other wires in there. When the time comes you need to pull a new one, you pull in the new by pulling out the old
That's why they invented cable lube. That number of turns is no obstacle, even with existing cables. But you should also have a pull cord spool.
To anyone reading this and assuming it applies equally to electrical conduit, it does not, which is why the NEC specs a maximum of four 90 degree bends between pull points. You could probably manage five, as was described, but it is technically disallowed (again, for electrical wiring - the NEC doesn’t care about networking).
Bends ideally need pull boxes, but given the lack of pull boxes, you might be able to use fish tape where where fish rods / glow rods don't work, if you cannot get a pullstring / pull cable going.
and always install extra guide wire
I sympathise with burying cables that you think are for life, only to need to replace them later.
We ran fibre cables in the ceiling when constructing our house. I requested the electrician to shield the cables with some tubing, but he probably thought I was being extreme. We have 9 cables, 2 of them don't work, likely from being bent by mistake or something.
The wiring is intermixed with electrical and ethernet (for cameras) cables, making the process a bit tricky. At least for us we might only have to cut the ceiling boards in a few places to help guide the replacement cables.
9/10 times the problem is at the terminator - they can get yanked out of position if they are pulled rather than the sleeve. Snip off the pulled end of the suspect line with Kevlar shears and shine an OFF down the other end - and you’ll probably see laser. It’s then a surprisingly simple job to re-terminate with mechanical connectors.
Upvote for posting about a failure. We should all be more vocal about our failures.
Anyone in the US military that has bought 'military grade' Bates shoes and pulled them out of a locker after a year just to see the soles disintegrate can likely tell you the value of 'military grade'.
Shoes need to be used, or the rubber and/or glue holding the sole on will deteriorate.
There's gotta be more to it than that. I've got a pair of dress shoes I wear maybe thee times a year at most, and I've had them for somewhere between ten and fifteen years, perhaps longer.
The soles (rubber because winter) are in perfect condition, and the leather isn't too bad either, though I've not really conditioned it enough and it's starting to show.
Both can be true. I have specifically heard that shoe glue needs to be repeatedly compressed to be maintained or it will disintegrate. Anecdotally as well, I had a pair of quality, lightly used, but old, hiking boots that had the sole completely separate after a day of heavy use. The runber sole completely detached from the leather shell inner shoe. The crazy thing was that BOTH boots failed within 20 minutes of each other.
And because they are military grade they need to be used for some military stuff.
I believe, he might have stored some solvent in the vicinity of the cable. Anyway it won't affect the optical performance of the cables. It's just the loss of mechanical protection. The disintegrating sheathing could be repaired by shrink tubing, which is more convenient than by wrapping it up in tape.
This is why you always bury a rugged, big diameter tube, and run the cables inside of that.
My friend also always runs multiple string lines through during construction. Later if a wire breaks or you want an additional cable or upgrade, you attach your new wire to a string and pull the string from the other end all the way through. If they had done this, they could have simply dragged a new fiber optic cable through.
You can pull the wire and second string together so you have always a single string in conduit.
Pvc also dries out and cracks. But yes.
If it’s underground (meaning not in the sun) the lifespan of PVC is 100+ years. It seems unlikely it will be his problem if it ever cracks.
PVC used in water pipes had some surprises, the lifespan there turned out to be less than optimistically expected when PVC pipes came to the market. 100 years might be hard to test for...
You can always splurge on some military grade pvc conduits :^)
Is it a humidity problem? in our climate in the Med all kinds of plastic, pu and rubberised materials will just start cracking and flaking after a year or two.
About page on OPs blog says Singapore, so yeah.
PU is especially vulnerable to degradation via hydrolysis.
I’d be acquiring or borrowing a fusion splicer and splice protectors then getting them into a fixed enclosure on the wall with socket outlets.
It seems like wizardry when you first see it, but actually fusion splicing fibre is not hard at all once you’ve done it a few times.
The most important part is the cleaving, always use a high quality cleaver.
Chances are very high the fibres themselves in the cables are absolutely fine, they are remarkably resilient given their size.
The link to the product says "TPU outer jacket". That's thermoplastic polyurethane, which is well known for degrading via hydrolysis:
https://en.wikipedia.org/wiki/Polyurethane#Hydrolysis_and_bi...
...so it is a bit amusing to see "TPU Jacket Features Water, Abrasion Resistance" in the product description. PVC or PE would be far better and more common.
> PVC or PE would be far better and more common.
Be aware, depending on where you live and where the cable goes, PVC and HDPE outer jackets may not be allowed due to fire safety issues. But yes, neither of those are prone to the same degradation over time, so in many cases they will be a good choice.
... Shucks. I should really have scrutinised the materials.
> A main component of why I was in sheer horror was the fact that I had stupidly buried all of these cables under my cement flooring in PVC trunking from my shelter to all of the rooms in the flat.
This I don't quite get .. as I understand it "PVC trunking" is a type of cable channeling / ducting.
I do a lot of cable and pipe layout around houses, farms, workshops, worksites, etc. and it's routine to use pipes / ducting / channels to allow other cables to be threaded through after or to replace bad cables.
As much as cable deterioration sucks it should be a relief to have ducting to pull good through after the bad.
The electricians mentioned that in order to curve the cables along underneath the floor tiling they couldn't use metal trunking which would cause sharp angles, so they used PVC pipes to do curvy trunking for the fibre cables. I could theoretically pull a new cable through by ripping out the wall outlet if this cable actually fails. You can see it in my earlier homelab post. But due to the length of the trunking and the number of bends, I'm not too sure if I can safely drag a new fibre cable through.
But yeah, maybe it's not that bad after all. I hope it won't get to that point.
I feel for you & yeah, fingers crossed :-)
One of my love / hates is Australian parrots and cockatoos - fantastic birds, noisy as hell - and they can rip out and shred unprotected wiring from rural camera and sensor systems like winged can openers.
> due to the length of the trunking and the number of bends, I'm not too sure if I can safely drag a new fibre cable through.
I saw someone commented elsewhere about a plastic bag and a vacuum. Another option to keep in mind is a lubricant intended specifically for the task of pulling cable through a conduit.
In the olden days, when things like TVs and VCRs had cabinets made from polystyrene and PVC-jacketed power cables, you'd often find that if something had been put away with the mains lead coiled up on top, it then left a "scar" on the case. This is because the plasticiser in the PVC jacket attacked the polystyrene, leaving the mains lead fragile and brittle and a nasty gooey mess on the case that you couldn't fix.
That's why the leads are wrapped in a polythene bag.
When people started using polystyrene sheet insulation in houses (thankfully they no longer do this!) the cables running inside the walls were affected in the same way, with the PVC insulation rotting off as the plasticiser leached out and attacked the polystyrene. Of course there you had the added joy of having a potential electrical fire with a source of just-about-inextinguishable fuel, the polystyrene foam made of fuel and air.
I wonder if something similar has happened here, something's gotten onto the fibre jackets and pulled the plasticiser out?
Would that be this item? [1] The product description and SKU match.
It's not clear who "FS" is. A reseller? A manufacturer? They seem to be in Singapore. There's no excuse for the external plastic sheath disintegrating. They must have formulated the plastic wrong. The terms specify a 30 day warranty.
Here's a catalog of real mil-spec fiber optic cables.[2] This is overkill for home applications; you put these in a fighter jet.
In between are Telecom Industry Association compliant fiber optic cables. That's what telcos use. There are US manufacturers with real plants and addresses.
[1] https://www.fs.com/products/70220.html
[2] https://www.glenair.com/catalogs/fiber-optics.pdf
FS is almost certainly fs.com, who do sell lots of fiber stuff.
I agree that less-than-milspec equipment should survive being installed in a home, but... this fiber didn't. https://news.ycombinator.com/item?id=46572962 seems to be relevant.
FS is a US company. They are a fairly reasonable option for third party networking equipment. We run a ton of their SPF+ transceivers in our racks, as they're significantly cheaper than OEM parts and indistinguishable in operation and we've had excellent support the handful of times we needed it over the years.
This looks like regular hydrolysis, same thing that happens to shoe soles after any number of years.
I don't think it's fair to make fun of the cable specifications, seems to me they held up just fine despite the jacket disintegrating. The article doesn't mention the error rate, but I wouldn't be surprised if it was still zero.
That's weird. Only place I've seen a rapid degradation of cables were those getting direct sunlight.
The conclusion paragraph seems doubtful to me though - unlikely that speeds will slow down from a cables external plastic flaking
I imagine there could be some slowdown if the exact wavelength of the transmission also happens to come in from outside where the jacket is missing.
What’s the advantage of using fiber optics for home networking over 10Gbe Ethernet?
Many people believe running fibre between buildings, even in ducts, is safer than running copper because you get opto-isolation from lightning.
The second thing is that domestic buildings usually do not come with a consistent ground plane. I worked in a 1960s build purpose made for mainframes and we had ~48v floating between racks at either end of the building and had to do a shitload of work to reground the building, in the 90s (-we were decommissioning an IBM 3033 and deploying a secondhand cray1) the point being somehow, God knows how, prior rs232 serial wiring didn't care and the ground plane for the mainframe was fine at the time. Pre Ethernet this stuff maybe just passed code.
I suspect people who build their own home to some spec acquire these theories. Data comms? Not much reason tbh unless you're pushing a lot more data than normal.
> The second thing is that domestic buildings usually do not come with a consistent ground plane.
Ordinary unshielded copper Ethernet doesn’t care: it’s transformer-isolated at both ends. Shielded cable may object to carrying any substantial amount of current through the shield.
Anyway, there are a handful of good reasons to use fiber:
- Length. Copper is specced for 100m. Panduit will sell fancy copper cable that they pinky-swear works for Ethernet at 150m. Single mode fiber will work at silly long distances.
- High bandwidth. Copper will do 10Gbps. High speed specs exist, but there is approximately zero commercial availability of anything beyond 10G using copper at any appreciable distance. Fiber has no such problems.
IMO if you are running fiber anywhere that makes it awkward to replace (i.e. not just within a single room), use single mode. Multimode fiber has gone through ~5 revisions over the last few decades, and the earlier ones have very unimpressive bandwidth capabilities at any reasonable distance. Even the latest version, where truly heroic engineering has gone into reducing modal dispersion, relies on fancy multistrand cables for the faster Ethernet speeds. Single-mode fiber, meanwhile, continues to work very well and supports truly huge bandwidth at rather long distances, and even decades-old fiber supports the latest standards. And the transceivers for single-mode fiber are no longer much more expensive than multimode transceivers.
It's one of those "just because" moments. The idea was to future proof my home infra for a 25G NAS connection. Most ethernet connections tap out at 10G. While theoretically speaking Cat 8 cables can do 40G, hardware support for full 40G Cat 8 NICs is rare. Fibre is very very flexible with its potential bandwidth and SFP28 transceivers are relatively affordable (if you don't do what I did by using SMF. Home networks should only use MMF if the property isn't a mansion.)
I still prefer SMF over MMF. It also allows me to "move" where the city fiber comes in and patch it to another location without any active hardware. So I can for example move my router into another room.
I ran SMF and have no regrets. https://sschueller.github.io/posts/wiring-a-home-with-fiber/
10GbE rj45 (normal ethernet jack) spf modules tend to burn power and get extremely hot, like to the point of burning you if you touch it - the manual for my switch said to leave adjacent ports unoccupied if using one of those. The fiber ones run cool to the touch.
Also, not needing to rerun any cabling if we want to bump up speeds in the future, you just change the laser module on either end. These should be good to >100x current speeds. Not the case with copper.
"10GBASE-T runs hot" is only half true.
The real problem here is that 10GBASE-T is ancient. The spec dates back to 2006! And worst of all: it only saw lukewarm adoption by the datacenter industry, so there hasn't really been a reason for manufacturers to refresh their lineups. This means that SFP+ transceiver you buy in 2026 might be using chips manufactured using a 20-year-old node. No wonder it is running hot!
2.5GBASE-T and 5GBASE-T are essentially using the same technology, but you don't hear anyone complaining about it running hot: hardware for this only recently started to become available due to consumer demand, so any hardware for that is being manufactured using more modern technology, which means a lower power use.
It's still going to consume more power than fiber, but a modern 10GBASE-T SFP+ transceiver should not be burning hot.
Realtek recently made a new 10GBASE-T NIC that consumes much less power:
https://www.servethehome.com/cheap-10gbe-realtek-rtl8127-nic...
Fiber runs cool because it's operating well within the physical capacity of the channel. Copper needs an incredibly high signal to noise ratio to overcome the limitations of its medium. Copper will consume 5-10x more power than fiber for the same # of bits transmitted.
10G is looking to be the end for twisted-pair copper.
25GBASE-T and 40GBASE-T were standardized 10 years ago, but there are still basically zero products available with support for it. The datacenter market just wasn't interested and chose to use fiber and DAC instead. Worst of all: it requires Cat8 cables and is limited to 30 meters. This means it can't reuse existing cabling, and doesn't have the reach for many home applications - OPs blog post mentions the longest run in their apartment being 55 meters.
Combine that with the general death of wired networking for home & office use, and it is extremely unlikely the market of hardcore tech enthusiasts is big enough to warrant massive investments into developing some kind of 25G-over-Cat6-for-100m standard.
10G is pretty much the standard for high-end gear these days. This means any kind of future-proof setup needs to be prepared for a future upgrade to a fiber-based technology.
Ethernet can be run over copper or fiber cabling, it's not an alternative to fiber networking. Assuming you meant what's the advantage of fiber over copper: you can use faster speeds, longer distances less power on fiber plus it's not electrically coupled.
(speeds: 100 gig today, but faster speeds are coming.)
They get less hot (especially the network adapters on the ends of them), can go a lot further, can be a lot denser (including being able to carry things other than Ethernet in the same bundle), and are a lot more future-proof (unless the cable jacket literally crumbles at the slightest movement in a few years).
If they're using spf+, it's almost certainly ethernet on the fiber. Do you mean, why not use copper twisted pair?
Ethernet runs on many mediums, as well as over the ether.
I kinda want some just 'cause it's cool, with the only problem being that I haven't been able to find an excuse to justify (to myself) needing it.
Also much lower power and heat.
This is the most compelling reason (unless you really need the range of fiber) - 10GbE can be really power hungry. Each 10G switch port that is in use adds something like 1-5 watts to the power budget. 1 watt is reasonable but most switch hardware isn't nearly that efficient. That could mean 10 watts for every single link if you're using 5 watts at each end. Multiply that by several links and it starts to add up really quickly.
For me, it was for a nearly 100ft run that try as I may to get a good termination, I'd often find my Mac Studio and Ubiquiti EdgeSwitch struggle to negotiate at more than 5gbps. So I got a smaller switch upstairs, ran 10GbE to it, approximately 10ft, and then ran OM-3 fiber for the 100ft up into my attic, across my house and down into the garage. Rock solid at 10 Gbps.
Server-grade fiber optics can get to terrabit/sec speeds. In other words, ludicrous speed.
(He’s gone, plaid!)
FS.com is great for all kinds of fiber stuff… but curiously, nothing long-distance. I never really understood it; you can get a 40-channel DWDM setup (including tunable 100gig SFPs) just like nothing, but a drum of quite normal G24 loose tube cabling meant for outdoor use? Nope. You'll have to go elsewhere for that. And I guess that's also what happened here; the poster picked the best thing they had for the purpose, and it's just not that good.
I've also had problems with their pigtails also being weird, by the way (layers separating so that automated cutters can't stretch the pigtail properly). It's weird when everything else is so good—it's as if they only care about what's going on internal to a data center and you never need to do a splice. :-)
I can confirm the pigtails issue. They are a huge pain to strip for whatever reason. Even cheap ones from AliExpress work better.
Was there a technical reason for not using corrugated ducts in the concrete, maybe because it's a shelter?
Andromeda strain
FYI "military grade" is code for "cheapest bidder."
So what should I buy, "telco"?
If it's any consolation, you can have fiber without jackets as long as they are cable-managed very carefully.
The coils are too tight. The tension on the plastic pulled it apart.
This is why should never-ever directly bury cables in the ground/walls/floor and ALWAYS use rigid PVC and/or flexible PVC tubes from site to site and pull the fiber or UTP cables through those tubes.
As an alternative if you are networking a single location and you don't mind seeing some finishing profiles on the walls (or want something easy in a pre-existing situation) you can also drill somewhere along the wall and feed the cables directly down to the floor or up the ceiling and cover them up.
But always, ALWAYS, make them easily accessible and easily removable.
Got plenty of experience to say no cable will survive a lifetime, and if you experience a problem without easy access you are fucked.
When you design, build or renovate your house, always plan for future replacement of cables and pipes!
Coiled up high-speed fiber optic cables suffer data-abrasion due to centrifugal forces. Either reduce data speed or arrange those cables in straight lines with space-grade angle connectors.
Worse still, the loop-de-loops can make your packets dizzy which is an unpleasant experience for anyone doing a video call with you and makes games such as VR chat completely untenable.
It does highly improve the QoS if you stream Sonic gameplay.
If the point of a home lab is to learn useful lessons where your customers don't pay for your stupidity (or more politely: your learning journey) then this guy's next employer is definitely getting their money's worth.
But that reminds me of something: I spend money on hobbies, but I spend the absolute minimum amount of money possible on home IT research and learning. Fuck that noise: if my employer wants a lab, they can damn well pay for one.
> military grade cable
Bruh