SmartOLT

LOSi errors on GPON networks and how to avoid them.

One easily overlooked cause of LOSi errors in GPON architectures is the colour matching of the fiber patch with the ONT.

Solution: Always match the color of the patch connector with the colour of the inside connector of the ONT, OLT or EDFA.

If the inside connector of the ONT has a blue color edge, use a blue patch/connector. Whenever you pass the signal from a blue color (SC-PC) to green(SC-APC) or vice-versa you lose between 3dBm up to 4 dBm, depending on circumstances and the quality of the patches.
Also, your chance to induce a back reflection on entire PON, rises. Thus, when mixing colours, it is possible that at some point, all the ONTs on a PON fiber wire to disconnect at the same time for a few seconds with the cause: LOSi.

Other causes for LOSi Error can be fiber twisted or bent excessively.

Recap:
Blue pairs with Blue.
Green goes with Green.
Black PON ports on the ONT pair with Blue patches.