Fiber Optic Networks

Quick Learn Fiber Optics Network

Unless you are going to be an actual fiber technician, you probably won’t need to know much about actually terminating it. You’ll be using pre-made fiber patch cables most of the time, and connecting to fiber distribution points that were put in by third party contractors. Following are quick learn fiber optics network.

Quick Learn Fiber Optics Network
1.Two basic types of fiber transceivers in use around the campus: SX and LX, generally speaking. SX is for Multimode, and is cheaper, but shorter range than LX, which is Singlemode and can easily go for kilometers. (you can remember this by just thinking “Short-range X” and “Long-range X”)

2.The fiber optical transceivers on either end need to match types because there are several wavelengths that can be used depending on the length of the run. Though, generally speaking most campuses just pick one that works for the longest run and just uses those so they don’t end up with twenty types of transceivers running around.

3.The network speed are depend on the type of fiber and the optics you use to connect it to your switch. General rule, single mode fiber goes faster over longer distances, needs a single mode SFP (1Gb optics) or SFP+ (10Gb optics). Multi-mode fiber, same as single mode but only fast over shorter distances and requires a multi mode SFP or SFP+. Single mode (long-haul) fiber is 9 microns in diameter and tends to carry high power lasers that carry for kilometers. Multimode (short-haul) is wider (I typically use 50 microns) and they run at lower power but are less expensive and go shorter distances.

4.Here are a few things you should know about SFPs, 10G SFP+, and 10G XFP modules which are the little plug-in transceiver modules that go into switches that you plug fibers into. If you are buying any of those to terminate a new fiber run into some network equipment, make sure you buy them with the digital optical monitoring (DOM) feature. Look at the data sheet of the SFP/SFP+/XFP you’re looking to buy and just make sure it’s on there. If not, find the equivalent model with DOM.

5.Learn about the fiber connector types. Most are going to be LC, but you will probably also see SC if using the older, big GBICs, and maybe ST for connecting to the wall/rack termination points. LC connectors are great for high density patch panels, and connecting to transceivers. If you need an ultra secure connection, then by all means go with an FC.

6.Fiber cables are not used as full-duplex in a single cable for most deployments yet. You have one strand that goes one direction, paired with one going the other. So you will be working with fiber pairs. They aren’t always patched correctly at the termination points, so you may need to take the patch cable ends apart and swap them around. They make the ends so that you can do that with a little effort.

7.An OTDR and even a simple light meter are hugely important for troubleshooting.

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