from Hacker News

If you get the chance, always run more extra network fiber cabling

by hggh on 3/25/25, 1:40 PM with 244 comments

• by msarrel on 3/25/25, 2:40 PM

  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!

• by bhouston on 3/25/25, 3:15 PM

  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.

• by timzaman on 3/25/25, 2:54 PM

  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++

• by runjake on 3/26/25, 1:59 PM

  If you have the choice, always run single-mode. It’s infinitely more scalable than multimode and the price is on-par. Around here, SMF is currently cheaper.

  SMF optics are single digit dollars more expensive than MMF optics, if you use third-party modules. And you might as well use them because your SP does. In my experience they’re better built and more reliable (longer lasting and lower failure rate. n=1000s of modules) than first-party Cisco optics.

• by JoshTriplett on 3/25/25, 3:44 PM

  No mention in the article of making sure to run conduit, so you can always add more cables easily.

• by protocolture on 3/25/25, 11:01 PM

  I recall working in a building that:

  1. Was the former HQ for a local telecom company 2. Was now an office building with a couple floors of data.

  Ages ago, one of the DC providers in the building had run 36 cores to the roof to service a telco.

  It was a massive undertaking, the building is riddled with asbestos and old plant. Had multiple renovations etc.

  Anyway, a few years later, every telco in the state wanted to be on that rooftop. And they had the only reliable means to service it with fibre. That 36 core became a massive profit generating asset, one that they could have monetised even further if they had have run 100 core instead. But it was never feasible to drill holes for a new duct (Asbestos regulations getting tighter), and it was never feasible to shut down 12 telcos for a day to use the existing fibre as a draw cable.

  Getting a single core rented here, and throwing on Bidi's, was like mana from the gods at the time.

• by jmacd on 3/25/25, 3:15 PM

  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.

• by chaz6 on 3/25/25, 5:51 PM

  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.

• by ggm on 3/25/25, 11:51 PM

  Not as a serious other-side but I knew an engineer associated with ARUP and during the time of Canary Wharf being in design, the plenum spaces were re-sized twice as a function of emerging pre-fibre burdens.

  I believe now, there is probably the equivalent of 3 or more floors of unused space, consumed by oversize plenum in the light of emerging fibre.

  I do believe fibre probably is a sensible end road for "small enough" and so pulling more of it, for the same radial bend and cable diameter probably makes sense.

  Also bear in mind "re clocking" by tuning the lambdas and deploying new lasers is a thing. That 100 pair fibre can be re-clocked across it's lifetime and be the equivalent of 1000 pairs in equivalent bandwidth, by the time you're done.

• by interroboink on 3/25/25, 10:25 PM

  “We’re only going to do this once and there’s always the unforeseen.”

  — Joseph Bazalgette, on doubling the pipe diameter when building the London sewer system

  (though I don't have an original source for that quote)

• by eemil on 3/26/25, 10:22 AM

  I'm surprised Chris left out a big reason: cable is cheap, and labor is expensive. And there are a lot of fixed costs that don't depend on the number of cables or their thickness.

  You might save a little bit going with 4 pairs instead of 24. But that goes out the window as soon as you need to run a single new cable. If you want to be stingy, pull the cables but leave them unterminated.

• by zelon88 on 3/25/25, 3:44 PM

  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.

• by js2 on 3/25/25, 2:24 PM

  > 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...

• by aftbit on 3/25/25, 2:43 PM

  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.

• by j45 on 3/25/25, 2:54 PM

  Originally thought this was excessive, but at least 4 per outlet/room. Saves buying a bunch of smaller switches.

  1 for a switch (Although VLans can help) 1 for telephony if required 1 for media devices / peripherals 1 extra

  Optional fun use of HDMI over ethernet for more runs.

  Behind TVs, you can break it down, or just run a bunch of runs.

• by sponaugle on 3/26/25, 2:49 PM

  In a home buildout, running fiber is surprisingly inexpensive and easy to do. There is one area to watch out for - In most US homes drywall is installed with screws that go into studs so if you have large bundles of wire or fiber be careful how the sit relative to the surface of the studs. Often the drywall screws will be off by a bit an miss the stud. If you wire bundle is large enough and it is a 2x4 wall vs a 2x6 wall you can lose a number of wires with a puncture.

  A second common problem is the wire installer pulling the fiber around sharp corners, sometimes with staples and zip ties. Fiber is surprisingly resilient, but very sharp bends will cause significant problems. Using armored fiber can help this a bit.

• by yetihehe on 3/25/25, 2:42 PM

  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...

• by hadlock on 3/26/25, 11:57 AM

  King County (Seattle) did this when wiring up the municipal network. Networking World ran at least two cover stories on this in the mid-1990s. They ran 200 ... bundles? Strands? Everywhere. That fiber is still there, under sidewalks, inside bridge structures, everywhere. Whoever bought the rights to that excess fiber from the city is probably subletting it to various FAANG and datacenters making a small fortune. That fiber runs through most of downtown seattle.

• by eqvinox on 3/25/25, 4:24 PM

  > 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.

• by cheema33 on 3/25/25, 3:44 PM

  I subscribe to this philosophy.

  I recently had my house remodeled. A lot of the walls were opened up and I asked the contractor to run fiber and cat 6a everywhere. Now every room has multiple drops of each. Even the outdoor and garage have several drops. Bathrooms have ethernet. Attic, basement and storage room has multiple drops. I may have overdone it. But, I never wanted to every worry about this ever again.

• by thefz on 3/25/25, 4:09 PM

  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.

• by Taniwha on 3/26/25, 9:35 AM

  And if you can't, always pull a string through the conduit .....

• by jonhohle on 3/25/25, 2:27 PM

  As the article says, this is true for just about any cabling, copper, power, etc.

  I’ve done cabling in two houses and I’ve never had too much. I’m always finding reasons to run more to new places.

• by em3rgent0rdr on 3/26/25, 3:16 AM

  Had a squirrel chew through the fiber internet cable going to our basement. Fortunately there was enough slack that the unchewed cable could still be pulled and reach the telephone pole and reconnect without having to redig the entire path, which would have cost much more.

• by DeathArrow on 3/26/25, 6:32 AM

  At home I have a pair of single mode fiber running in each room, it is future proof enough for me.

  ATM running at 1Gbps, but I will soon upgrade the router, switches, SFP+ modules to run at 10Gbps since my internet provider will upgrade the offering from 2.3 Gbps to 10 Gbps this year.

• by olalonde on 3/26/25, 1:31 AM

  YAGNI: You Are Gonna Need It.