Key wavelengths for the telecom operator are normally 1310, 1490, 1550nm for testing the network at operational wavelengths and 1625nm for confirming good installation practices (macro bending for example). This Applications Engineering Note (AEN 135) explains and recommends standard measurement methods for characterizing optical fiber system performance. This note also provides background information on system link configurations, test equipment and system component considerations that influence. this document is the property of JDSU. No part of this book may be reproduced or utilized in any form or means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without pe n optical fiber to a distant receiver. Such a comprehensive approach to fiber optic cable testing. Fiber Optic Testing Testing is used to evaluate the performance of fiber optic components, cable plants and systems. Obviously, the latter is a much more difficult measurement. Quality verification ensures that optical fibers meet attenuation, continuity, geometry, and mechanical integrity requirements before being placed into service. In FTTH, ODN, and data center deployments.