Question about fiber

[kylebrogers]

Note:  This is 50u fiber running approx 100m. 

On each end of the fiber connection is a media converter converting it to ethernet.  Currently it is using a pair of 100BaseT-FX converters and everything works great.  When we pull those out and replace them with 1000BaseT-SX converters we get all green connection lights on the converters but no traffic.  What are we doing wrong? 

[Leo Laohoo]

If you put those two 1 Gbps media converters side by side and patch them with a patch cord, does the link go up?

[bbaillie]

Hi,

Check the patch cords, possibly one or both are 62.5 um. At 100FX the patch cords work sometimes, but at 1000SX the link may be up but no traffic passes, lots of CRCs.

The second item may be your media converters only operate at 1000T and don't support auto negotiation of speed on the copper side. The devices you are using are not locked at 1000 T to match media converters if this is the case.

Cheers,

Brian