05 November 2015

Fiber Networks Demystified


Just to be clear, I am a Sys Admin.  I am NOT a Fiber specialist, or a Fiber installer, etc.  It used to be that fiber networking was something we dealt with after it was installed.  We might buy specific hardware, or have it provided for us.  For most sys-admins and network techs, fiber was a magic place that worked, and worked well.  If it broke.... we had bad days.  The reality is, fiber networking is not that complicated.  There are, believe it or not, more standards for copper cable than there are for fiber.  We only use a few standards for either one.... so stop getting freaked out.

In the beginning there was OM1.  This orange, 62.5µm cable has been a part of most major installs since the mid 70's.  It is fragile, has limited range, and limited modal bandwidth.  It DOES, however, still have 3 times the max distance of CAT 5, 5e, 6,or 7.  My biggest problem with old OM1 (Old Military 1) is that it is much more fragile than the other cable types.

We then moved to 50µm cable for LED driven optical networks.  It was great.  It doubled the max distance for data transmissions, it's more durable, it has double the modal bandwidth of OM1.  What it did not do, was efficiently transport laser optics, because like the OM1 fiber, it had imperfections in the core of the fiber, so you have to use a conditioning cable at launch.

Enter OM3 and OM4, laser Optimized and laser Enhanced fiber.  These two are designed to be more efficient with laser optics, but will also carry LED optics more effectively.

Why not that Single Mode Fiber.... that goes farther.  Sure.  It does...  9µm single mode cable is capable of something like 80km.   Single mode fiber is different from multimode fiber in the way light travels along the fiber.


 The question, then, is what you are in need of, and if you are going beyond 1100m.  Single mode fiber has even fewer standards than multimode.  


Standard    
Wavelength
Max Range
10GBASE-LR
1310 nm
10 km
10GBASE-ER
1550 nm
40 km
10GBASE-ZR
1550 nm
80 km

Multimode has a few more options.



Ethernet Standards
Speed
Standard
Media
Distance
1 Gb/s 
1000BASE-T
Cat 5/5e/6/7
100m
1000BASE-SX 
OM1
300m
OM2
600m
OM3
1000m
OM4
1100m
1000BASE-LX
OM1-OM4
550m
1000BASE-LX/LH
SMF
10km
1000BASE-ZX
SMF
70km
10 Gb/s
10GBASE-SR 
OM1
30m
OM2
150m
OM3
300m
OM4
550m
10GBASE-LRM 
OM1
220m
OM2
260m
OM3-OM4
400m
10GBASE-T 
Cat 6 (unshielded)
55m
Cat 7/6 (shielded)
100m
10GBASE-LX4
SMF
10km
10GBASE-ER
SMF
40km
10GBASE-ZR
SMF
120km
40 Gb/s
40GBASE-SR4 
OM3
100m
OM4
150m
100 Gb/s
100GBASE-SR10 
OM3
100m
OM4
150m

To be honest, pick your speed, pick your distance, and you will have your standard and cable.  In my opinion, if you are running 1Gb, use SX optics, if you are running 10Gb, run SR.... done.

I mentioned different fiber cables before.  I need to be clear.  Even though OM3 and OM4 are optimized for laser, they will still run your SX network.  OM3 and OM4 are backwards compatible.

You might want to click on this chart to view the larger version....


The 2 big rules are:

1) Don't Mix and Match.  You can do that with CAT-whatever, you can't with fiber.

2) Keep it clean.  We are talking about glass and light... even the grease from your hands will get you dirty packets..

Also, as an aside.  Be nice to the next guy, or gal, that works on your fiber.  Stop using ST cable connectors.  They are stupid, and my fat fingers can't use them in tight spaces.  You have other options.



In short.  Don't make yourself crazy.  It will all work out.  

I have compiled everything into a "Fiber Demystified Cheat Sheet"  Use it... enjoy it.  If you find mistakes, leave a comment bellow!






Disclaimer
The information contained in this website is for general information purposes only. The information is provided by Tomas Voboril and while I endeavored to keep the information up to date and correct, I make no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, suitability or availability with respect to the cheat sheet or the information, products, services, or related graphics contained on the website for any purpose. Any reliance you place on such information is therefore strictly at your own risk. In no event will I be liable for any loss or damage, including, without limitation, indirect or consequential loss or damage, or any loss or damage whatsoever arising from loss of data or profits arising out of, or in connection with, the use of this website. Always check with your Vendor, Systems Admin, and Installer before making major decisions. 


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