Passive Optical Networks

7.3.3 Network Testing, Characterization, and

Diagnosis Guidelines

All fiber cable plants require certain basic tests to assure they were installed

correctly and will meet expected performance values. After a PON network is

installed and put into operation, the inevitable optical-fiber cable plant and

communication electronic degradation and failures will occur. The operational

anomalies or failures that might occur at an ONT, an OLT, or distribution

cabinet include: (1) degradation of fiber connectors resulting from moisture,

dirt, damage, or misalignment; (2) OLT or ONT circuit card failure; (3) per-

formance degradation in an ONT resulting from other customer-connected equip-

ment; and (4) malicious and accidental damage to cables, distribution