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SFP+ to RJ45 connection

jgreco

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Thank you for the responses and information.

That seems doable. I've been Googling and I'm assuming I need OM4 Fiber Optic cable then some SFP+ connectors/wall jacks? That was the downside in my mind of running SFP straight to my desktop, as it's about a 30 foot run and would require getting another new card for the desktop.

Is there a particular advantage to doing things this way versus swapping for an RJ45 Intel (for the NAS), then picking up that 10gbe switch?

Of course I'm impatient and already ordered 50 feet of cat6a, connectors and installation tools last night :p
Well the big advantage to fiber is that it actually works, if you play by the rules, without drama even. 10G Category cable is subject to lots of drama because it burns more watts, is higher latency, and has tragic length limits.

10G SFP+ is a little nasty for beginners because it seems so "foreign", what with no RJ45's, and these weird SFP module thingys, and a bewildering array of connectors and types of fiber, which is what caused me to write the 10G Networking Primer. But the cold truth is that this stuff has been successfully deployed in data centers for the last SEVENTEEN years. By way of comparison, I wrote back in 2014 that I felt that 10G copper was about to make a big entrance, and would ultimately prevail because it was "simpler", despite being a lower quality (think: "VHS of the networking world") product. Here I am five years later, pleasantly wrong-ish. There's still very few cheap 10G copper switches, little overall adoption, etc.

Perhaps this makes sense. Copper's a crappy technology.

10G copper chipsets typically require at least 3W to sustain a connection, and this can go as high as about 10W to drive a long run. By comparison, SFP+ ports are spec'd for 2.5W *MAX*, normally using less than 1W, and with that, I can put in an SR (think: "short range") optic and with OM4 I can run as far as 400 meters without a problem. Or I can put in an LR (think: "long reach") optic for a run up to ten KILOMETERS.

10G copper chipsets normally introduce around 3 microseconds of latency in processing, whereas SFP+ is typically around 300 nanoseconds, or about 1/10th as much, making SFP+ a better choice for performance.

https://www.datacenterknowledge.com...-benefits-of-deploying-sfp-fiber-vs-10gbase-t

Is somewhat dated at this point but still generally correct-ish.

But I think the real suppressor is that there just isn't much demand. When we reached 1Gbps, this was really sufficient for most general end-user computing needs, and because it took a decade for 10G copper to evolve, people had a decade in which to appreciate that they weren't really being killed by the constraint of 1Gbps, and for dirt-cheap 1G switches and cards to be produced. I can create a cheap 1G network with two 1G ethernet cards and a switch for about $50. Now try that trick with 10G. Most people simply won't swallow the cost differential. Even here, the core network is all 10/40G, but end user machines are 1G.

Anyways, probably more than you wanted to know. What you DO need to know:

You don't need OM4. OM3 is good enough. But OM4 is dirt-frickin-cheap too.

As an example, FS.COM 5 meter OM3 for $4.30. You can order a wide variety of prebuilts, which sometimes aren't actually in stock, so be looking at the ship date. You can choose OM3, OM4, the length of your choice, make sure to select LC for both ends, select an appropriate jacket (depends if you're running in-wall or have fire code requirements), etc. I suggest the thick 3mm stuff for beginners. I do this stuff professionally and the 0.9mm stuff still freaks me out a bit.

https://extranet.www.sol.net/files/misc/biffiber.jpg

That last one is OM4 BIF duplex "uniboot" with a 2mm jacket. Crazy stuff. We're switching over to it, all ordered custom length. Very cool, and really not that pricey.
 

danb35

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Using that Mikrotik for example -- That would require:
1) An SFP+ cable from the NAS to the switch
Correct.
2) Cat6a cable, with a transceiver, from the switch to the wall jack
Correct.
3) Cat6a cable, with a transceiver, from the switch to my router
No, a normal Cat 5e or better cable would do--the Mikrotik has one GbE port which you could use for that purpose. And your question about internet access has already been answered: yes, that will cover it.

All these answers are the same for the Aruba switch Chris has mentioned, or for the Dell 5524 switch I mentioned above; both of them just have lots more GbE ports.

Edit: A couple more things. (1) Chelsio are wrong that their cards will only work with their optics; there are other vendors (like the aforementioned fs.com) who sell compatible optics. fs.com even sell a SFP+/RJ45 module that probably is (or could be made) compatible with Chelsio, but it's very expensive. (2) I think I'd favor the Dell 5524 over the Aruba switch Chris mentions--it's cheaper; it does everything I understand you need to do (specifically, that you only ever intend to have two machines at 10G); the 10G ports work as such right out of the box; all the manuals and firmware are available for free, direct from Dell, without any kind of support plan; and many if not all of them come with a "lifetime" warranty. But both it and the Aruba are rack-mount switches designed for the enterprise. I don't recall my 5524 being especially noisy (the 5524P I replaced it with is a bit louder), but it certainly isn't silent. The Aruba won't be either. If that's a problem for you, you'll need to be aware of it.

Of the COAs under discussion, though, I think I'm favoring Chris's suggestion--put a SFP+ card in your desktop, get a SFP+ switch with an appropriate number of ports, and run either a SFP+ DAC or (better) fiber between the two.
 
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Chris Moore

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Is there a particular advantage to doing things this way versus swapping for an RJ45 Intel (for the NAS), then picking up that 10gbe s
Cost is the factor that I considered I bought the switch for $150 (now $125)and four 10Gb network cards for around $ 25 each and some of the network cards I bought came with SFP+ to fiber transceivers and others came with DAC cables. I only needed to spend a little more for some fiber optic cable and take the time to run the fiber. All of it cost me less than $300 and I put 4 systems on 10Gb networking with 48 1Gb ports that every thing else can connect to. I'll probably get one of the small switches suggested by @danb35 if I need more ports.
Spending less money on the solution is part of the puzzle.
 
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danb35

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I'm thinking it might make more sense to ditch SFP+ altogether and just order an Intel X540-T1
So that's a $275 NIC, plus a $250 switch, or $525. Compare that to my suggestion of the Dell 5524 ($80), a SFP+ NIC for your desktop (say, the Chelsio T420 for under $150--others are cheaper, but this will improve performance and reduce power use), two compatible SFP+ optics from fs.com at $16 each, and a fiber patch cable of the appropriate length--$262 plus the cable.

Edit: Besides, the w a n k (seriously, board? Do you need to replace that word with "panda"?) factor of the "gaming" gear is way too high for my taste.
 
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JenWest1919

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Wow, thank you so much for all the responses! I suppose sticking with SFP+ makes sense... I'll see if I can return all the cat6a cable I ordered...

Questions!


My run from the switch to my wall jack could be 35 feet, not 50. I assume extra cabling is not a problem or should I be measuring to reduce having to do a wrap/bundle?


My confusion lies with the "Connector Type".

When I look up SFP+ cables, they have connectors that look like this:


And I look up LC UPC connectors, they look like this:


So I'm assuming there is another part of the equation I am missing? Some additional connectors/transceivers? I'm guessing this is what that Chelsio branded module is for (someone on Amazon said this is an "LC" module)? I'm guessing I'd also need some sort of special SFP+ wall jack connector, too?
 

Elliot Dierksen

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Here is a good link that describes the different connector types: http://www.thefoa.org/tech/connID.htm
You can get fiber patch cords with one kind of connector on one side, and a different one on the other. ST type (short for stab and twist) is one of the oldest one as far as I know. The LC's are the ones I see most now. I think that is primarily because that is one of the smaller form factors, and about the only one that would fit on an SFP/SFP+ type transceiver. You can coil fiber, but you do have to be careful about how tight you bend it. It is at the end of the day, GLASS! :) I would stay away from ST. For the wall jack part of it, I would stay with SC or LC. No matter what kind of connector you use, you have to be aware that you may have to swap them around to make sure you get TX to RX.
 

danb35

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So I'm assuming there is another part of the equation I am missing?
I'm pretty sure most, if not all, of this is covered in @jgreco's 10G primer, but here goes in a short version.

There are two ways to go from SFP+ to SFP+: a direct-attach cable (DAC), which you show a picture of above; or optics on both ends and a suitable fiber patch cable. The latter is generally preferred for running any significant length.

For the optics, get these: https://www.fs.com/products/11552.html Be sure you tell fs.com to make the modules compatible with whatever equipment you're using (NIC or switch, you'll need one for each).

For the fiber, I like these: https://www.fs.com/products/68477.html They aren't the cheapest cables, but they have both fibers in a single jacket making them very compact, and they are pretty tolerant of bending. They'll make them to any length you need, though it may incur a bit of a delay.

Terminate them in your wall or patch panel with these: https://smile.amazon.com/gp/product/B01B5AG0TI/ref=ppx_yo_dt_b_asin_title_o05__o00_s01?ie=UTF8&psc=1 for a neater job.
 

danb35

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For the wall jack part of it, I would stay with SC or LC.
Really, just LC--keep it simple.
No matter what kind of connector you use, you have to be aware that you may have to swap them around to make sure you get TX to RX.
This is something I've wondered about. The Uniboot patch cables make the issue moot, of course, but many patch cables don't have the individual LC connectors joined. I've hooked up a few of them and never had them not work. Have I just been lucky? Or do the optics sort that stuff out on their own?
 

Elliot Dierksen

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This is something I've wondered about. The Uniboot patch cables make the issue moot, of course, but many patch cables don't have the individual LC connectors joined. I've hooked up a few of them and never had them not work. Have I just been lucky? Or do the optics sort that stuff out on their own?
In my admittedly limited knowledge of this, I don't think there is such a thing as auto cross-over in the fiber world. When I hook things up, having to swap connector position is a fairly regular occurrence.
 

danb35

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I don't think there is such a thing as auto cross-over in the fiber world.
So thinking this through a bit, that means that these cables must be made with a crossover. After all, they work, and it's impossible to switch the LC connectors around. So if I connect two SFP+ optics using one of those cables, I get a connection. But if I connect two of those cables using a coupler like this, it wouldn't work. Seems like a straightforward enough experiment.
 

Elliot Dierksen

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So thinking this through a bit, that means that these cables must be made with a crossover. After all, they work, and it's impossible to switch the LC connectors around. So if I connect two SFP+ optics using one of those cables, I get a connection. But if I connect two of those cables using a coupler like this, it wouldn't work. Seems like a straightforward enough experiment.
Yes, that has been my experience. When you get duplex fiber patch cords with the connectors in a holder, they are crossed. When you go direct from one device to another, this is perfect. Where it is not perfect is if you are connecting to juction box(es)/patch panel(s) where things could get crossed over multiple times.
 

jgreco

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Really, just LC--keep it simple.
Agree!!

This is something I've wondered about. The Uniboot patch cables make the issue moot, of course, but many patch cables don't have the individual LC connectors joined. I've hooked up a few of them and never had them not work. Have I just been lucky? Or do the optics sort that stuff out on their own?
The optics have a fixed TX and RX. The nature of the technology does not allow them to "sort that stuff out."

So, the following is the geek equivalent warning to "do not point a gun at anything you wouldn't shoot." Do not use your eyes to look into the optics of an energized SFP, a fiber patch, etc.

Take your cell phone and point its camera at the end of an SFP SX or SFP+ SR optic. The resulting picture should show one port seems to be "lighter" - that's the LED or laser. If your optic is installed "label up" then this will be the right-hand port.

Now there are two big things that can happen.

One: You can order crappy fiber patch from a discount manufacturer. This stuff usually comes looking like the crap was thrown together by some poor soul working for pennies a day. The zipcord has been ripped apart for a foot or two, the individual fibers aren't marked, and the ends might not even be in a dual LC clip, and if they are, they might be backwards.

High quality fiber is distinguishable because it looks like someone tried. The zipcord is ripped apart only a few inches, and ideally banded with heatshrink to prevent further ripping. The individual fibers are marked with little clips "A" and "B", or "1" and "2", and/or maybe the strain reliefs are white and yellow, meaning someone has done the work of identifying the fiber. "A"/"1"/white goes into the LEFT port on one end and the RIGHT port on the other end. RX-to-TX and TX-to-RX. The end sports a little removable clip that keeps the two connector housings in the proper order.

Two: When your data center guys are running cross-connects, they often are doing what we call "field termination", which means they have a thousand foot spool of fiber and they put ends on where they want. So in a variation on the "poor soul working for pennies a day" issue, they might not get the ordering right at your demarcation point, or at an intermediate MMR, or something like that. Often it seems like they simply don't bother to check.

So in the data center, we frequently check the work. For an unlit pair, shining a flashlight in one side of one end and checking with a cell phone camera is quick and easy. Many DC techs omit the duplex LC clip and you can just pull the data center's side of the coupler and fix it.

And if you're missing the duplex LC clip, I highly suggest you just get some. Cheap/easy fix. When you put them on your patches, shine a light in one side, looking at the other end, and make sure the fibers "cross over."
 

Elliot Dierksen

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So in the data center, we frequently check the work. For an unlit pair, shining a flashlight in one side of one end and checking with a cell phone camera is quick and easy. Many DC techs omit the duplex LC clip and you can just pull the data center's side of the coupler and fix it.
In a backwater Florida town that I will decline to name, I encountered some techs at a small vocational center who thought flashlights were the end all be all of fiber test equipment. I was there installing network equipment, and that particularly incident is still burned into my brain 20 years later. I was waiting for the "Deliverance" banjo music to playing....
 

jgreco

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Yes, that has been my experience. When you get duplex fiber patch cords with the connectors in a holder, they are crossed. When you go direct from one device to another, this is perfect. Where it is not perfect is if you are connecting to juction box(es)/patch panel(s) where things could get crossed over multiple times.
Correct. Wireheads (or whatever you call your cabling guys) are expected to make this work correctly but often don't. It's sad when you have to do someone else's job for them.
 

jgreco

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In a backwater Florida town that I will decline to name, I encountered some techs at a small vocational center who thought flashlights were the end all be all of fiber test equipment.
They graduated and went on to be Google Fiber designers, who thought microtrenching in asphalt or concrete was going to be a suitable long-term technology...??

A flashlight is fine for identifying A/B fibers but that's really about it. I happen to do it because I have a very bright Maglite LED on my belt at all times. Handy at the damnedest times.

I was there installing network equipment, and that particularly incident is still burned into my brain 20 years later. I was waiting for the "Deliverance" banjo music to playing....
I was once driving through backwater Florida, actually very pleasant, and we came upon signs for "Florida Cracker Weekend"... I just went "wow" and scratched my head.

https://en.wikipedia.org/wiki/Cracker_(term)

Apparently though it is actually a non-pejorative at least in some cases.
 

Jessep

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Less flexible than standard as you would expect but not stiff. Gives a lot more peace of mind. I use it at home and we use it between racks at work.
 

JenWest1919

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Thank you for all the responses and detailed information! I'm finally starting to wrap my head around this project. Thank you!

I've come up with a tentative list of supplies I'll need based off your comments and suggestions here.

Does everything look right? The only concern (other than I've noted below in bold), is the issue with @danb35 mentioning "that means that these cables must be made with a crossover." Did I pick the right cables or am I going to need something not listed here?

Switch:
https://www.balticnetworks.com/mikrotik-4-port-sfp-802-3at-af-switch-l5.html

Switch Optics (Mikrotik CRS305-1G-4S+IN):
https://www.fs.com/products/50000.html
https://i.imgur.com/mCvEnfF.jpg

Desktop NIC (I'm running Windows 10):
https://www.amazon.com/10Gtek-E10G41BTDAG1P5-Ethernet-Converged-X520-DA1/dp/B01LZRSQM9/

Question: Would it make more sense to skip a new NIC and get an SFP+ to RJ45 for my existing setup? A bit off topic but I vaguely remember when building out the PC that between my GPU, Intel Optane AIC, and two M.2's in a RAID, that there may be an issue with PCI bandwidth. If adding a NIC could potentially cause a problem with that, would I be losing anything by going with a transceiver instead of a new NIC?

Desktop Optics:
https://www.fs.com/products/50000.html
https://i.imgur.com/FvtTl7P.jpg

Nas NIC:
https://www.chelsio.com/nic/unified-wire-adapters/t520-so-cr/

NAS NIC Optics (Chelsio T520-SO-CR):
https://www.fs.com/products/50000.html
https://i.imgur.com/8T22pTj.jpg

Cabling (NAS to Switch, Switch to Wall Plate, and Wall Plate to Desktop NIC)
https://www.fs.com/products/68573.html

Question: What "Connector Type" do I choose? The options are "Flat Clip", "Standard Clip", "Switchable" and "Push Pull". Google failed me (Or maybe I failed Google).

Keystone Coupler for Switch to Wall Plate:
"Fiber Optic Keystone Coupler - LC to LC Multimode Duplex"
https://www.amazon.com/Fiber-Optic-Keystone-Coupler-Multimode/dp/B0062NCJ1C/

Keystone Wall Plate:
https://www.amazon.com/Mediabridge-Keystone-Plate-1-Port-White/dp/B071KWMNDT/

Am I missing something?!
 
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