It is interesting to contrast measurements necessary to qualify a fiber optic cable installation against those of a copper cable installation. To certify a copper installation it is important to consider wiremap, length, attenuation, NEXT and PSNEXT at both ends, ACR at both ends, ELFEXT at both ends, return loss at both ends, delay, and delay skew. In contrast, to certify a fiber installation only attenuation, at one or two wavelengths, is usually measured. Length may also be measured or physically recorded. Fiber cable can be tested one fiber at a time using the end-to-end technique. This methodology uses an optical source and power meter for direct measurement of attenuation. The fibers are tested, results recorded and later compared to an industry or user-defined standard to evaluate the success of the installation. For those who test fiber frequently, new fiber test technology is available for quicker, more productive network testing and certification.

Optical Time Domain Reflectometers (OTDRs) are used for troubleshooting fiber optic cabling. An OTDR can measure optical length and display the distance to an optical event (fiber break, end of fiber, fiber splice or connector). OTDR are not suitable for making end-to-end power loss measurements.

We expect the use of LAN fiber networks to become more commonplace as technology and costs improve. Fiber standards do exist and networks should be tested to the appropriate application standard (Ethernet, FDDI, ATM) when possible. If unknown, a general commercial building standard such as TIA-568B or ISO 11801 should be followed. Network designers and equipment venders may have proprietary standards that must be followed. A range of test tools are available to ensure that you can accurately and reliably test fiber networks.