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konigl Tue, 09/02/2003 - 09:01
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Well, I suppose you can physically attach monomode (or single mode) fiber with SC connectors to those interfaces; but it's not a good idea. It may work for short distances, but do not rely on it.


Those two interfaces are designed to launch optical signals into a 62.5/125-micron multimode fiber. Single mode fiber is typically 9/125-micron in diameter. (The first number is the diameter of the fiber strand or core; the second number is the diameter of the core plus the cladding material surrounding the core.)


If you use single mode instead of multimode cable, you reduce the cross-section surface area of the core at the end of the cable (called the "launch aperture") by over 96%. So, much of the light emitted from the TX port on your interface will never even make it into the cable.


If you are going to use a fiber patch cable to connect those two interfaces, use multimode. 100BASE-FX is rated to 2km over multimode when the interfaces are configured to run full duplex. (This drops to 412m, if half duplex.)


If you must use single mode fiber, then you will need multimode to single mode media converters at each end of the span. Several companies manufacture these; Transition Networks (www.transition.com) makes the ones I use.


Hope this helps.


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