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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 n
by msarrel 2y ago
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!
- cyptus 2y ago_minimum_ bend?
- zygentoma 2y agominimum bend _radius_ A straight cable has an infinite radius, the more bend the smaller the radius
- hinkley 2y agoThough 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.
- jagged-chisel 2y agoIf you’re using the planet as your “flat surface” then sure. If, however, you’re willing to deal with exiting the atmosphere at each end, you can use Real Straightness. But I don’t know anyone running a single segment for that distance.
- hinkley 2y agoI’m sure there are some microwave antennas still out there doing the Lord’s Work. At least in the Plains states where hills are low and putting antennas on two of them gives you some extra distance. How far do microwaves bend over the horizon?
- aaronax 2y agoDon't they generally do the opposite of bend over the horizon? Two towers that are observed (visible wavelength = tiny Fresnel zone) to have line-of-site can easily be obstructed (microwave = huge Fresnel zone). https://en.wikipedia.org/wiki/Fresnel_zone https://en.wikipedia.org/wiki/Fresnel_zone
- tejtm 2y ago> How far do microwaves bend over the horizon? that depends on the weather and frequency among other things https://en.wikipedia.org/wiki/Line-of-sight_propagation https://en.wikipedia.org/wiki/Line-of-sight_propagation
- connicpu 2y agoIf you're going out of the atmosphere may as well skip the fiber and just point lasers through the vacuum of space directly and reap the benefits of the faster speed of light through a vacuum vs glass!
- scarby2 2y agoworks great until a group of space bats get in the way.
- Etheryte 2y agoMinimum bend radius.
- quickthrowman 2y agoIt’s usually 20x the outer diameter of the cable for fiber, a cable with a .3 inch OD has a 6 inch minimum bend radius.
- DannyBee 2y agoWhat? This is 100% wrong. This is well standardized. As I posted elsewhere: G.657A1/B1 = 10mm (half an inch) G.657A2/B2 = 7.5mm (a little over a quarter inch) G.657A3/B3 = 2.5mm (less than 1/8th of an inch) The only cable you will find with a 6 inch bend radius is going to be armored interlocking fiber cable or something. You can take 2mm G657.A3 fiber cable, wrap it around a pencil, and it will work 100% fine. Even old G652 cable only had a 1 inch bend radius.
- quickthrowman 2y agoIf I am wrong, then explain why this 24-strand plenum rated fiber optic cable has a minimum bend radius of 5.9”: https://leviton.com/content/dam/leviton/network-solutions/product_documents/product_specification/Leviton-Spec-IO-Plenum-Adventum-LTP.pdf https://leviton.com/content/dam/leviton/network-solutions/pr... Part number: LTP12B024 I am running a project where the low voltage contractor is pulling this fiber cable into a conduit my electricians are installing. I don’t doubt your bend radius claims on the fiber optic cables you listed, but there are far more types of fiber cable than the ones you listed.
- deleted 2y ago[deleted]
- DannyBee 2y agoThere are not far more types of fiber cable, there are far more types of jackets :) You are confusing the cable jacket with the fiber cable inside of it. This is the spec on the jacket they use and they didn't design this particular jacket to be flexible enough to survive flexing at the level the fiber cable inside of it can. Sure - not all jackets can be bent as much as the fiber. Some because they are not made to be as flexible (as here), some because it's basically impossible (armored interlocking jackets), etc. I'm not sure what this changes? The part number with suffix AB0403 (the SMF A1 fiber), if you cut the jacket, you should be able to bend the fiber cable inside at a radius of 10mm and have it be fine. It appears to be standard G.657A1 fiber cable inside. There are really not far more types of fiber cable than i listed, and this spec sheet definitely does nothing to support that claim, since as i said, it has A1 fiber cable inside the cable jacket that will happily support a 10mm bend radius. BTW, as an aside, I wouldn't use this stuff - just looking at this sheet and pricing at my normal fiber distributors - it is both overpriced and underspec'ed for its price. Which seems pretty typical for leviton :) Most 24 standard I/O plenum cable is going to be 7.8mm (this is 9.9, so 30% thicker), and have less than half that bend radius even with non-flexible OFNP rated jackets. If you are being charged more than 2 bucks a foot for it, you should consider other options.
- numpad0 2y agoFibers can be bent to a radius of an inch or so, that's the tolerated minimum bend radius. I guess you could call it "the maximum sharpness tangency" or something like that, but that's not the standard verbiage.
- DannyBee 2y agoG.657A1, which is basically the crappiest you would ever buy at this point, is not even half an inch bend radius.
- _JamesA_ 2y agoHave fusion splicers come down in price? Can you recommend any?
- Faaak 2y agoYou can have them second hand for ~500€ on ebay
- tonetegeatinst 2y agoAny 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.
- mmastrac 2y agoAliExpress 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 2y agoFor Multimode, they now make splices where you jam the two cleaved ends into the splice. It costs about $5 per splice.
- DannyBee 2y agoYou don't need them unless you are running a mile or two of fiber - mechanical fast connectors (IE no polish, etc) are less than 0.3db loss at this point. Fusion splicing will still be 0.01db or better, but you will be well within the power budget of any transceiver you find with mechanical connectors, if we are talking home networking - even a 2km 10gb transceiver that is 20 bucks has a 6db power budget. Heck, the 10km are cheaper than 2km at this point - 17bucks on amazon, power budget of 16db.
- 2y ago
- whycome 2y agoYour typical Rodent Accelerated Transmission Signal And System Suppression
- liotier 2y ago> Yup, always run extra everything Cables ain't free, duct capacity is finite and duct rental from the local incumbent is costly too... Please calculate the financial optimum of pay now vs. pay later - taking into account growth, various forms of attrition, cost of capital, opportunity costs and appetite for risk. Or everyone would be running 1152 strands cables everywhere. But then I see that from a telco perspective and, now that I've read the article, it seems to be from a small-scale hosting perspective - entirely different economics.
- dwattttt 2y agoOr, take the money you would spend calculating that, and that's the amount you spend for your margin.
- liotier 2y agoHaha, I'll tell that to the outside plant capacity planning team ! But seriously, I'm telco-biased, and it seems that the article has a small scale hosting... Different worlds. At small scale, sure - the bigger cable is a rounding error.
- terribleperson 2y agoDuct capacity is finite, but fiber cables are tiny and they are very nearly free compared to the cost of having them run.
- liotier 2y agoNot quite tiny - a basic armored (rats !) 12 strands cable may be around 10-15 millimeters, whereas similarly specced cables in the 500 strands range might reach 20-30 mm. In crowded Paris downtown, it adds up fast. On the countryside, that is a lot more weight to hang on poles.
- throwaway2037 2y ago> Paris downtown Where is downtown Paris? 1/2/3 arrondissement? I never heard the term used for Paris. Mostly, it is used to describe the Wall Street area of Manhattan (NYC) as the island is relatively north-south and Wall Street is on the southern end.
- DannyBee 2y ago"And be careful of the minimum bend radius." The minimum bend radius of any good fiber is way less than cat6 at this point. G.657A1/B1 = 10mm G.657A2/B2 = 7.5mm G.657A3/B3= 2.5mm CAT6 = 25mm Flexible cat6 = 15mm. Fiber surpassed copper for flexibility almost 2 decades ago (G.657 was introduced in 2006, but let's call it 5 years before all forms became common). Even G.652 was only 25mm and standardized in 1984.
- Dylan16807 2y agoIt takes less force to bend, though.
- mrheosuper 2y agocould be solved by running reinforce wire along it
- traceroute66 2y ago> could be solved by running reinforce wire along it You could, but you might as well just use armoured fibre if you're doing that ! Some of the low core-count CSTA stuff out there these days could almost have you thinking its unarmored if you didn't know. Not at all bulky.
- walrus01 2y agofor an example of how good modern g.657 bend loss insensitive fiber is, for ftth applications and drop/last hundred meters, here's an example of it being abused with a staple gun and the resulting loss in dB. https://www.youtube.com/watch?v=h4wzJSInvww https://www.youtube.com/watch?v=h4wzJSInvww the above is from 12 years ago I've seen some g.657.b3 patch cords and work done for FTTH installs that are absolutely atrocious and yet continue to function properly.
- Gareth321 2y agoThis is proprietary technology and is definitely NOT representative of normal fibre cables. I know because I had had to deal with contractors doing exactly this, which crushed the cables we ran. There are many things which could be better if we were willing to pay higher prices for them. At the end of the day, cheap and good enough usually wins.
- pavelstoev 2y agoAnd clean the fiber connector ends with a special cloth or cleaning liquid. Once, I had an intermittent link due to dust particles. Fun fact 1: When you don't have a proper OTDR fiber tester to check for breaks, you can shine a laser pointer down the fiber and see it projected out on a sheet of paper on the other end (you might have to call the person on the other end). Fun fact 2: If the other end is plugged into a transceiver, don't look at the fiber end directly; instead, look at it through your phone camera. If all is working correctly, you should be able to see a faint purple light out of one of the strands. P.S. always remember to roll it if no link initially :)
- rowanG077 2y agoThe last one may not work anymore. A ton of phones nowadays have IR filters.
- moron4hire 2y agoThey all do and always have, they just aren't perfect.
- rowanG077 2y agoReally? I thought they usually used to have no filters, especially on the front camera. Well of course the lenses always filtered some IR light, but I wouldn't call that a filter, they also "filter" non IR light. A filter to me is a dedicated element or coating that prevents the majority of IR to be transmitted.
- pavelstoev 2y agoworks on my iphone 13
- traceroute66 2y ago> If the other end is plugged into a transceiver, don't look at the fiber end directly Let me fix that for you. Don't look at the fiber end directly, always assume it is plugged in unless you can see the other end yourself with your own eyes. Fibre light meters can be bought cheaply for a basic troubleshooting bag kit-out if you don't fancy splashing out on a fancy device.