Newbie question: Can I connect SX to LX GBIC?

[ariesto.kosasih]

If I have 2 switches within 5 meter distance... but one is LX and one is SX, will it work if I connect them both together?

Thank's in advance.

[Prashanth Krishnappa]

No you cannot mix GBICs on the same link

[konigl]

To be more specific, you cannot mix them because the optics operate at different wavelengths. SX GBICs operate at 850-nanometer, and LX/LH GBICs operate at 1300-nanometer. They won't "see" each other.

Also, I think there's a subtle difference in the way the GBICs put the light into the fiber: SX GBICs put it out off-set from the center of the fiber strand, in a way that generates multiple modes ("multimode"); LX/LH GBICs put it out down the center, so that there's a "single mode". When LX/LH GBICs are used with multimode fiber, they generally need a mode conditioning launch cable, that takes the single mode output of the LX/LH GBIC and steps it into the multimode fiber in such a way as to avoid flaws in the center of the multimode fiber strand, essentially "multimoding" it. Because the optical power is stronger, and because of the characteristics of the 1300-nm light, it lets you go farther on multimode fiber (550m) than the SX GBICs (220-275m).

Hope that helps.

[ariesto.kosasih]

Thank you very much.... now I learn something new! :)

It helps a lot!

-Ariesto

[steinar.haug]

On the other hand, you can under certain circumstances use LX/LH and

ZX GBICs together. We have a link where this was used because *one*

of the original ZX GBICs was malfunctioning, and replacing it with an LX

just worked. LX at both ends could not be used due to length/loss budget.

(It is out of spec, and you can of course not count on *any* support for such

a mix of GBICs - thus definitely not recommended. But it's nice to know

that it can be done in a pinch.)