Fiber Optic Cabinets, Cables, Pedestals and Terminals

The end goal when constructing a fiber network is to create strong, clear fiber connectivity across the board. This ensures the fastest signal is provided to the customer, whether commercial or residential, and the least amount of future downtime due to service outages.

For network builders who want to maximize their yield from their fiber networks, fiber testing is of utmost importance. This doesn’t mean simply testing in a single direction, but bi-directionally as well. Here are a few reasons why bi-directional fiber testing is essential today.

Preventive Measures

One of the most obvious reasons such testing is conducted is to prevent future issues that may arise from improper installation. If a fiber connection has not been tested, there’s no way to detect issues that could result in maintenance and repair costs later. This works both ways, hence the necessity for bi-directional testing.

When a fiber connection is tested, both the Insertion Loss and Optical Return Loss will be measured. With each connection made, the signal transmitted down the fiber loses some of its potency as light is lost during the connection. Adhering to the network provider’s specifications will ensure the signal is getting where it needs to go with minimal insertion loss or refraction.

Conducting more thorough testing first can mean less trouble later. By verifying the validity of the connection during installation, network providers will save time, energy, and money on potential future service calls and operational costs.

Avoid False Positives and Negatives

Bi-directional fiber testing can also resolve issues that may arise from false positives and negatives throughout a network. When testing from one direction only, perceived spikes in signal loss or gain can be misleading. For example, variances in mode fields between spliced fibers may look like an increase in signal strength (or a gainer), when it really means the opposite. Similarly, a false negative occurs from a perceived loss of signal, which may be the result of a bad splice, but it could also be a gainer read from the wrong direction.

This is a tricky situation, in that a splice failing due to either of these issues will offer the same result even after you re-splice. The next course of action would seem to be to replace either of the fiber sections that were spliced together, which can be costly and difficult in many situations. Network providers need a way to avoid activation delays or penalties from such faulty connections, and that’s where bi-directional testing comes in.

By performing testing in both directions, you can avoid the confusion that comes from false positives and negatives. Such testing averages out potential measurement differences, allowing you to diagnose the real problem that needs to be addressed.

At Clearfield, we offer a selection of fiber training courses to enhance your learning and skills development. Don’t waste time and resources due to improper testing. To learn how to test your fiber the right way first, visit our training and certifications page now.


Gavin Rummler assists with the marketing efforts for Clearfield as the team’s Corporate Communications Specialist. He joined the company in 2022, utilizing his communications expertise to author written collateral across various channels. Before joining Clearfield, he worked in multiple communications roles, including curriculum writing, technical writing, and copywriting.

Cookies