The 40km single mode transiver work for a 200m connection?

[JCDINIZ]

Hello Guys,

I need to connect Datacenter A to Datacenter B using optical fiber, the distance between point A and point B is 200m.
In the architecture I have an HPE Flex Fabric 5940 JH395A switch and the 40km single mode JG234A transiver.

Does this connection work even though my distance is shorter?

[parnassus · Accepted solution]

It depends...if I'm not mistaken...since there would be an absolute maximum difference of 5dB between the Maximum declared Tx Power (+4dBm) and the Maximum declared Rx Power (-1dBm) of your JG234A ER (Extended Reach) SFP+ Transceiver...your link will need at least 5dB attenuation end-to-end to work properly.

Your 200 meter run (which is Single Mode 9/125 um, right?) OTDR measured loss is what? Attenuator usage (Yes versus No) depends also on that answer.

Consider that JG234A works with a central wavelength of 1550 nm...so if your 200 meters long run is made of Single Mode fiber 9/125 um...thus it could easily reach, let me say, 0.25 dB/km (or better)...this means only a 0.2 km x 0.25 dB/km = 0.05 dB loss for the main path of 200 meters (excluding, if any, losses of any splice eventually present - totally possible that such short run hasn't splices at all) and not considering any other patches/connectors additional losses which would add some loss into the whole path.

Once you have all losses properly accounted (Path+Slices+Connectors+Patches), you will be able to figure out if attenuators are needed and their required (dB) value...basically you should have losses at least equal (if not more than) the difference of 5 dB found above.