[c-nsp] OT: Multimode fiber question

[Bill Wichers]

> This is perhaps Off-Topic for this list, but I'm not sure of where else
> may be a good place to ask...
> We have two buildings with 62.5 micron multimode fiber connecting them
> together. The fiber jumpers I've been given to use are 50 micron.
>
> I've got to get this link up and going now, so I'm going to use what I
> have, but I plan on having the 62.5 micron jumpers ordered to replace
> the 50 micron ones.
>
> Are there any issues I can expect to see by having the 50 micron jumpers
> on the 62.5 micron cable?

As long as you're not already pushing the limits for the reach of your
optics (which should be around 250-275 meters for gig SX on 62.5/125u
cable), it should work fine. It's not a "good" idea, but it should work.
You'll have extra loss (optical power, not packet) due to reflection on
the 50u fiber cables (aperature mismatch), but that's about it. Dispersion
won't be a problem as long as you are within the limit for the *worse* of
the two fiber types (which should be the 62.5u in this case).

You should use the correct patch cords once you have them available though.

     -Bill


*****************************
Waveform Technology
Systems Engineer