OTDRFile

OTDRFile is a C#/.Net library designed to read data files from OTDR measurement devices.

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What is OTDRFile?

OTDRFile is an open-source C#/.NET library that enables developers to read and parse data files from Optical Time Domain Reflectometer (OTDR) measurement devices. These devices are critical tools used by fiber optic technicians to test, troubleshoot, and certify fiber optic cable installations.

An attractive screenshot of the example code from the repo

The library provides a lightweight, efficient interface to access OTDR measurement data while preserving the original data structure and format. It’s designed to be vendor-agnostic, supporting the OpenSOD (Open Standard OTDR Data) format defined in RFC 0001.

OTDRFile is designed to be as thin as possible, preserving the structure of the original data as much as possible, making no attemtpt to normalize data from devices manufactured by different vendors.

The implementation is split into three core sections:

DataTypes - Holds raw data in data scructures that are as close to the binary file format as possible.
Implementation - Wraps the DataTypes with scructures that apply the relevent scaling factors and converts fixed-point decimals into double-precision floats..
Internal - Provides helper layers, constants, and extensions to improve the efficiency of the data parsing.

Understanding OTDR Technology

Optical Time Domain Reflectometry is a sophisticated testing technique that works by sending pulses of light down a fiber optic cable and measuring the backscattered light that returns. This allows technicians to:

Detect faults and breaks in fiber optic cables through characteristic signal spikes and drops
Identify poor splices and bends that cause signal degradation
Measure total fiber length and signal loss across the entire cable run
Certify installations meet required specifications before service activation
Localize problems to specific points along the fiber for targeted repairs

Why Should You Care?

For Telecommunications Companies

Automation Potential: Build custom analytics tools to automatically process thousands of OTDR test results
Quality Assurance: Develop standardized testing workflows and compliance checking systems
Cost Reduction: Reduce manual analysis time and improve fault detection accuracy

For Software Developers

Clean API Design: Two-layer architecture (DataTypes, Implementation) provides access to raw data and representational fields; handling conversions for you.
Performance Optimized: Parallel parsing capabilities for efficient processing of large datasets
Open Source Freedom: Apache 2.0 license allows commercial use without restrictive licensing fees

For Network Operations Teams

Data Liberation: Extract test data from proprietary device formats for integration with existing monitoring systems
Historical Analysis: Build databases of test results to track fiber degradation over time
Cross-Vendor Compatibility: Work with data from multiple OTDR manufacturers in a unified format

Key Features

Lightweight Design: Minimal overhead with focus on preserving original data structure
Automatic Scaling: Handles conversion of fixed-point decimals and applies scaling factors transparently
Parallel Processing: Efficient parsing of large OTDR files using modern .NET capabilities
OpenSOD Compliance: Full support for the open standard, ensuring long-term data accessibility

The Bottom Line

As fiber optic networks become the backbone of global communications infrastructure, the ability to efficiently process and analyze OTDR test data becomes increasingly critical. OTDRFile removes the barriers to accessing this data, enabling organizations to build sophisticated fiber management systems, automate quality control processes, and ultimately deliver more reliable connectivity services.

Whether you’re maintaining a campus network, managing a telecommunications backbone, or developing next-generation network monitoring tools, OTDRFile provides the foundation for turning raw OTDR measurements into actionable insights.

Standards and compliance

OTDRFile provides the ability to read data compliant with OpenSOD - RFC 0001. It should also be able to load SOR data compliant with SR-4731 (Issues 1 & 2), but as we have never seen SR-4731, or any derrivatives thereof, we cannot verify this.

Disclaimer

This library is written without knowledge of Ericsson’s (or any other rights holder’s) intellectual property and has been constructed independently by the Authors. Any compatibility with the Standard OTDR Record as defined by SR-4731 (Issue 2) or any derivative or preceding works thereof is circumstantial and is not guaranteed by the authors.

Using this library with the intent of being compliant with any formats other than the format defined by OpenSOD RFC 0001 is at your own risk.

If readers require a library that is fully compatible with the SOR format as defined by SR-4731 (or derivatives), then they should purchase the relevant documents from the rights holders of that standard.

License

The software in this repository is released under the Apache License 2.0. A copy of this license has been provided in the file LICENSE.md. For a helpful summary of the license check out: https://choosealicense.com/licenses/apache-2.0/

Support

This is a free library licensed under the MIT license, if you notice a bug or have a feature request please raise a ticket in GitLab, and we’ll do our best to support you. If you need priority support or wish to fast-track a feature request, you’re welcome to engage us to answer your request.

Copyright Statement

License: Apache 2.0 | GitHub: github.com/BaldrAI/OTDRFile | Standard: OpenSOD RFC 0001

Open Source overview