Alot of problems with fibre optic networks are caused by dirty or damaged connector faces.
But how do you know?
The answer generally is you don't because connectors are rarely inspected as a microscope or video probe is required to magnify the connector to be able to inspect it. This is where the FIP-400 video probe from Exfo comes into play.
Available in 2 versions 200/400x or 400x magnification, the FIP-400 can resolve dirt particles down to 1um.
The FIP-400 can be plugged into a laptop computer with the aid of a USB adaptor, many of Exfo's OTDR's, AXS-110, FTB-1, FTB-200 or FTB-500 or it can be supplied with its own display either in the small form factor AXS-110 style or the FTB-1 format with the larger screen and the capability to take the ConnectorMax software option.
Not sure if you need one, then take a look at the video on this page which demonstrates how dirty/damaged an optical connector can get and that cleanliness is all important when dealing with fibre optic connectors.