If you get the chance, always run more extra network fiber cabling
86 comments
·March 25, 2025msarrel
whycome
Your typical Rodent Accelerated Transmission Signal And System Suppression
cyptus
_minimum_ bend?
zygentoma
minimum bend _radius_
A straight cable has an infinite radius, the more bend the smaller the radius
hinkley
Though if it is on or under the surface of the earth, “straight” will be a bend radius of around 6,370km. We don’t make a lot of buildings that deal with this but transcontinental or transoceanic cables certainly do. If someone designed a fiber that required absolutely no bend in order to work you’d have to use it in buildings or dig much deeper holes.
There was an encoding mechanism proposed about 10-15 years ago that used spirally polarized light to carry more channels, but it required the surface of the fiber to be polished to a much higher degree than existing cables in order for the light to go around bends properly.
Etheryte
Minimum bend radius.
_JamesA_
Have fusion splicers come down in price? Can you recommend any?
mmastrac
AliExpress sells some basic ones from $300-700 CAD ($200-500 USD) with reasonable reviews.
Whatever you do, don't try using the razor-style "hand splicers" and adhesive splice kits. Without a splicer that has a scope, you're just making bets each time that are difficult to test.
I've learned the hard way that it's just not worth it unless you can _see_ what you're working on.
tw_wankette
For Multimode, they now make splices where you jam the two cleaved ends into the splice. It costs about $5 per splice.
Faaak
You can have them second hand for ~500€ on ebay
tonetegeatinst
Any advice on making sure you get a good splicer?
I know a little about fiber connectors, and the different connector modules for speed, but I am not really sure what I need for a splicer for fiber.
JoshTriplett
No mention in the article of making sure to run conduit, so you can always add more cables easily.
paulkon
This right here is important. We could be running fiber end to end in the near future. Ethernet would end up obsolete like the phone line.
fach
How would running fiber make Ethernet obsolete? Physical medium and framing on the wire are fairly orthogonal.
JoshTriplett
People commonly use the word "Ethernet" to mean "Ethernet cable", as in a copper cable with an RJ45 on it, not just "Ethernet protocol", which is used over both copper and fiber alike.
timzaman
1. High-level, the post is all wrong. The point should be that you always need to make sure you can pull new cable. The poster illustrates this: single mode, multi mode, non-fiber, etc, etc. And if one "goes bad", you still can't run a new one, unless you have a pullstring.
2. The post cannot apply to fast/large networks - will be prohibitively expensive.
3. If running a few at home, I suggest to run MTP/MPO. It's basically a structured cable that can have around 12 fibers in them, plenty of future expansion.
Though I'll always run a large awg >>cat6 everywhere so it supports PoE++
stronglikedan
> And if one "goes bad", you still can't run a new one, unless you have a pullstring.
The one that went bad is the pullstring.
hinkley
Pull strings don’t give you a way to pull new cables. They give you a backup way to pull new cables. Every cable in a conduit can be used to pull its own replacement or 2. But if anything goes wrong, you have a second chance before you have to go find the fishing rod.
dsr_
> 2. The post cannot apply to fast/large networks - will be prohibitively expensive.
The expensive parts of fast/large networks are not the fiber strands.
* right of use / lease
* trenching and laying and covering
* amplifiers on long lines
* repair/maintenance
* endpoints
... which is why the first thing you upgrade are the endpoints, and the last you do is lay more fiber. Get the most you can afford (often physically) at the beginning.
bananapub
what a bizarre reply.
the author is a sysadmin, who can definitely change what is plugged in to the switches their employer has chosen to buy, but doesn't have the power to make physical changes between multiple buildings, easily authorise opex spending on cable pullers or retrain as a cable puller.
please actually consider what you're replying to before pushing the REPLY button.
bhouston
Yeah, we got a new house built 4 years ago and one of the biggest regrets is not enough ethernet outlets (running fibre in the house isn't practical yet) and power outlets in various places. It is really hard to think of all the places you would want them ahead of time unfortunately and as each has a cost you don't want to incur it unnecessarily.
But my biggest regrets were:
- Only a single ethernet port in the basement. Then the kid wanted a gaming station and we moved where the TV was. I should have put like 4 down there.
- No ethernet ports in the garage, I should have put in one for an AP.
- 4 ceiling APs instead of just two in the main part of the house. I over-estimated how much coverage I would get from ceiling APs and thus I have some APs hidden under furniture to ensure 100% house coverage.
- Lack of multiple circuits in the garage, even better a separate sub-panel with 6 outlets. I took up wood working and with a single circuit and 2 outlets was insufficient. That cost me $1200 for the sub-panel.
- Multiple outlets on the back and side of the house - I would have done two at the front on each side and two at the back on side each and one on each side of the house. I have a single outlet at the front and back and that is just not sufficient for lights, decorations and patio devices.
david422
> Only a single ethernet port in the basement. Then the kid wanted a gaming station and we moved where the TV was. I should have put like 4 down there.
Just drop a switch down there.
bhouston
I have, but now I have cable running along the base boards. That isn't optimal. Also I have 10G networking, so the ethernet switches are hot and expensive.
npodbielski
I was thinking about this and it is very expensive. And do I need 10G really? I do not think so. I did calculated few things when I was thinking about 10G and most probably I will not saturate 1G for few years. And with phones ans laptops mostly WiFi is used anyways.
So can I ask you what is the advantage for using 10G equipment in your case? Even something really dull like network card costs around 100€.
zdp7
You don't need an expensive switch. Five port 2.5G + SFP+ with poe can be pretty affordable and shouldn't run very hot.
mjevans
IMO a not-tiny house should have several sub-panels: Kitchen (enough to run the big stove + ~100A, but every outlet it's own 20A circuit), 'lab' / workshop (same idea), laundry room (lock-out breaker near / in room for connecting / disconnecting), etc.
A family member who's doing better in life than I am purchased a house built within the last 5 years, and it didn't even _have_ Ethernet run anywhere. WHY!?! I can't fathom how it's possible anyone would find that a negative.
nkurz
> A family member who's doing better in life than I am purchased a house built within the last 5 years, and it didn't even _have_ Ethernet run anywhere. WHY!?! I can't fathom how it's possible anyone would find that a negative.
I'm less sure. Are there any 40 year old cables that you'd consider a positive in your house today? 20 year old cables? I wouldn't be too excited about having a house full of Coax, 10Base-T, and twisted pair.
I feel like the much better solution is to run conduit in which you can replace the cable rather than permanently putting in twice as much of whatever is in favor today. The conduit is always better, right?
epiccoleman
> 20 year old cables?
I just bought a new house and the previous owner had phone lines everywhere (bedrooms, kitchen, office, rec room - honestly kind of weird). The house was built in 2002 and I gather that it was common at that time to put in Cat5e and just not use all the pairs.
So all it took was a pleasant afternoon with the circuit toner, a new patch panel, and a few keystone jacks, and now the house is networked beautifully. Sure, they're not in exactly the places I'd have dropped 'em if I'd been starting from scratch, but it's hard to beat cables already in the wall for zero effort!
bhouston
Yeah, conduit makes sense. The future in homes - from this current vantage point - is likely all wireless via multiple APs around the house that have short range but very high bandwidth. Only us power users will have wired ethernet.
nkrisc
> Only a single ethernet port in the basement. Then the kid wanted a gaming station and we moved where the TV was. I should have put like 4 down there.
https://store.ui.com/us/en/category/all-switching/products/u...
Unless you meant with regards to routing the cables throughout the space, like now it’s on the opposite wall from the port.
I’ve definitely shoved cables under baseboards, but you can also pull them off and the run the cable in the wall behind them. You don’t even need to patch the drywall then. You can also get baseboards (that look nice in a home) then double as cable runs.
jmacd
Wow, we recently built a house and this reads just like my regret list!
I think because there are less code specifications for the garage, builders just don't bother.
mmastrac
If you have any way to pull cables between floors, try pulling DAC cables. They give you 10+G, require no splicing (hardware can be found cheap now), and generally just work as you'd expect.
With a 10G backbone, you can get away with basement->main and main->upstairs in a three-floor house, with a small bridge on your main floor.
bhouston
> If you have any way to pull cables between floors, try pulling DAC cables.
Many of my devices take 10G ethernet, like MacMini and my MacBook Air docking station. Is there an easy way to convert from DAC to 10G Ethernet? The desktop has an SPF+ card so that will take DAC no problem.
Unfortunately there is no way to pull an any cables easily. But someone else suggested replaceable baseboards that hide cable runs, I should look into that.
realityking
I don’t know any media converter that would work for that but you can get a Thunderbolt SFP+ ethernet adapter. For example: https://www.sonnettech.com/product/solo10g-sfp-tb3/overview....
mmastrac
10G media converters are available for < $50 USD, but TBH I've never used one.
Epa095
Why DAC cables over Cat6a or Cat7
bhouston
10G Ethernet seems to be really hot, all my SPF+ connectors are hot, my TP-Link 10G switch is hot. It seems not be efficient anymore in that regards.
While my 10G fiber and 10G SPF+ DAC cables are perfectly cool.
I hope this is temporary but 10G Ethernet seems hot. I haven't seen anyone write on this topic yet but it is my findings.
graton
They are the lowest power way to connect SFP. And they are cheap.
Though I'm not sure I would pull them as they tend to max out at around 6-7 meters. I use them to connect systems within the same rack/room.
yjftsjthsd-h
> Only a single ethernet port in the basement. Then the kid wanted a gaming station and we moved where the TV was. I should have put like 4 down there.
Is it so bad to put in a switch?
bhouston
It does sort of suck because I have cabling running along the baseboards. Also I have 10G networking so the switches are costly and hot at least this generation.
ajsnigrutin
That's why pretty much every office space/building over here has cable trunking/channels on the walls instead of fixed wiring, eg:
https://www.elba.si/izdelki/parapetni-kanali/
https://www.obo.si/izdelki/izdelkiinstalacije-v-zgradbah/bis...
Need one more outlet? Remove the plastic cover, insert cable, insert outlet, cut the plastic cover to make space for outlet, and you're done.
jmacd
I just had this experience. I had a 200ft run between my house and barn. The original builder put a direct bury ethernet between the two and it failed. I dug a trench, put in a conduit, pulled 2 fibre lines and left a pull string in.
I recently had the primary fibre fail and am now on the backup. If I need to pull new ones in the future I can do that pretty easily through the conduit.
bityard
Yep. Direct-burial ethernet is surprisingly vulnerable to nearby lightning strikes. It's not a matter of IF the cable or devices get damaged, it's a matter of when. Nearby (not even direct) lightning induces ground voltage potentials between buildings to the tune of hundreds of volts or more.
zelon88
We've almost come full circle with the idea of "run more cabling" already in some ways.
For example, a building built in 1960 had analog phone lines. Then in the 80s network lines were added. Then in the 90s - 00s more and more and more network were added.
Then in the 2010-2020's we're starting to wind back down. Removing switches and racks that used to be fully populated with CAT5 which are now mostly empty. The end devices that needed these runs are now running on WiFi.
zelon88
To elaborate a little bit;
I've been in many, many buildings for cabling issues. While I generally agree with your assessment of "run more everything" I think this could be taken out of hand for a lot of smaller IT departments who aren't capable of using more advanced methods of network building. Like subnetting, VLAN trunking, or redundant links.
Why would you need to learn about these things if you've got 3 or 4 more pairs of fiber hanging down? Then you have a situation that I've seen before, where you have 2 fiber runs carrying flat networks right next to each other with just a couple of IP phones on each one.
chaz6
My business is fiber broadband, and we are laying as much as we can! Fortunately the legislative environment in the UK is conducive to this goal. For now we provide XGS PON (10Gbs minus overhead), with 50G PON becoming available in some locations later this year. Unlike regular point-to-point, it is point-to-multipoint through the use of optical splitters with one head-end port capable of servicing up to 256 clients. With the UK being so far behind most other developed countries, it means it can take advances in all of the R&D from the last twenty years. It has also led to the strange situation where there are some properties that have a choice between 4 or even more fibre network providers. Some fiber networks are tied to a single ISP whereas others are open to wholesale. I am not sure if there are any ISP's that support multiple connections to the same property via different fiber networks - but I think you would generally want to use a different ISP for each network anyway. IPv6 is supposed to make that easier, though in practice there are still no protocols (a la MEF 17 Service OAM) for the ONT to signal to the router that there is a fault condition. This is one circumstance where PPPoE is useful. As the UK has been slow to deploy fiber there are many ISPs still using it. I found this out the hard way when I made the switch. My trusty old Ubiquiti Edgerouter Lite (Cavium silicon) is not capable of hardware offload for ipv6+pppoe+vlan at the same time, so anything particularly demanding on IPv6 (e.g. Steam) essentially locks up the router. I will be trying out an Alta Labs Route10 this week to see if it provides any improvement.
js2
> Some of the time this fiber failure is (probably) because a raccoon got into your machine room
Or into your handhole/vault, along with her babies:
https://old.reddit.com/r/FiberOptics/comments/1ji3rrt/its_no...
aftbit
Regarding single mode vs multi-mode ... other than cost, is there any reason at all to run multi-mode fiber in 2025? I was under the impression that single mode was better in basically every way.
fleventynine
Multi-mode transceivers used to be a lot cheaper than single mode, but now they're around the same price for short distances. From what I can tell, most datacenters appear to be making the switch to single mode even for in-room networking.
FredFS456
Multimode transceivers are still a slight bit cheaper ($30 for 10GBASE-LR vs $22 for 10GBASE-SR on fs.com) but that's more than offset by the single mode fiber being slightly cheaper, even for short distances.
fleventynine
Apples to oranges. SR is for short runs inside a building. LR is for sending signals across a city.
For short runs inside a building, the transceiver prices are much more comparable. Compare https://www.fs.com/products/251819.html?now_cid=4089 to https://www.fs.com/products/282973.html?now_cid=4089
hinkley
Why does multi mode sound like it should carry more bandwidth but from context seems to be the less interesting option?
damnitpeter
Mode is simply the wavepattern of the light traveling through the optical fiber. Multimode means there are a few different wavepatterns traveling down the fiber, they tend to potentially interfere and its not as efficient of a use of optical power. In singlemode, this is a lot harder to do and requires better optics, the light is in one pattern, power is efficiently allocated to that pattern, and thus the light can be sent much further. Its been many years since college so hopefully that explanation suffices.
Now lets say you want to send multiple signals to get more bandwidth on one fiber, you just need to move the frequency/wavelength of light so different signals have different wavelengths and can be discerned at the receiving end. That's gonna take even more optics and filters on both ends, but works quite well to add more bandwidth to existing fiber installations where running more fiber would cost a lot more than installing new equipment on the ends.
FuriouslyAdrift
It's DAC in rack and then fiber or copper between spine and leaf (depends on distance, etc).
DanAtC
No. Just run single mode.
thefz
Cost, and marginally, heat of the transceivers.
yetihehe
I left one small room in my new home without network cabling, finished just before covid. Guess where my home office ended up being located...
thefz
I was under the impression that once laid, fiber is the most stable and future proof between all mediums (barring physical damage). After all it won't rot, stain or degrade like copper. It's plastic, mostly.
eqvinox
It is, it's just not immune to physical damage. Rodents and Jackhammers…
FuriouslyAdrift
Backhoes can find fiber from miles away... they hunger for it
eqvinox
> Fiber comes in two varieties, single mode and multi-mode. I don't know enough to know if you should make a point of running both[…]
Let me fill this in: in 2025 you (and everybody else) should be running SMF. If you need to directly connect to existing MMF you should run that additionally. But do not build MMF-only in 2025. It's akin to installing Cat5 (non-E) or even Cat3. And you pay mostly for the work, not the cable. Do yourself a favour and put SMF in.
FuriouslyAdrift
Agreed. SMF can handle nearly anything. A single strand can handle 100Gb 10km for OS1 or 100km for OS2 per frequency and you can do multiple frequencies at the same time or go bidirectional, too.
Yup, always run extra everything. At least you can splice fiber now. And be careful of the minimum bend radius.
Once, in the 90s, we were having intermittent network failures in our data center. I kept trying to troubleshoot it with the fluke, but the problem kept moving. When I pulled up the raised floor, I discovered that rats were eating the exterior sheath of the network cables. That was some fun troubleshooting!