As data centres, high-speed, high-density fibre networks expand to accommodate escalating demands, network engineers encounter heightened pressure to establish robust fibre connections with utmost speed and precision. One-cord reference testing has emerged as a pivotal methodology to address these challenges effectively, as discussed by Vincent Racine, Senior Product Line Manager, EXFO in this blog post.

Deploying a cutting-edge AI data center within an unprecedented timeline is no small feat. When a trailblazing hyperscaler set out to build a facility with 100,000 interconnected GPUs and 400G/800G technology, they faced daunting challenges that could have delayed the entire project:

  • Unprecedented timelines: Moving from concept to full deployment in a matter of months required flawless execution.
  • Complex fiber infrastructure: A web of singlemode and multimode fibers, coupled with multi-fiber connectors, added extra layers of complexity.
  • Interoperability headaches: Multiple vendors, test methods, and equipment led to confusion, miscommunication, and costly delays.

In the middle of this fast-paced, high-stakes environment, success came down to finding the right expertise and solutions to overcome these issues.

See how EXFO multi-fibre testing solutions transformed daunting infrastructure challenges into a case study in efficiency.

The Fundamentals of Fibre Testing

Prior to delving into the intricacies of one-cord referencing, it is imperative to understand the essence of fibre testing. During the setup or maintenance of fibre-optic networks, technicians must meticulously assess three fundamental aspects:

  • Insertion Loss: The extent to which the signal diminishes as light traverses the fibre.
  • Length: The complete length of the fibre, which directly impacts signal quality and serves as an indicator of its proper configuration.
  • Polarity: The verification of the correct direction of signal transmission from the sender to the receiver.

These factors ensure that the network operates in accordance with industry standards and regulations. However, conventional testing methods often entail intricate setups involving numerous cords and adapters, particularly when dealing with diverse types of connectors.

 

 

The Impact of One-Cord Referencing

One-cord referencing significantly simplifies this process. It can be likened to employing a single template to maintain consistency when cutting numerous pieces of material. Duplex one-cord referencing utilises a single cord to simultaneously assess both the transmit (TX) and receive (RX) paths of a duplex cable. This method eliminates the necessity for numerous cords and adapters, thereby enhancing the overall efficiency of the testing process.

One-Cord Referencing for Data Centre Deployments

Industry Standards Compliance:

Fibre networks are mandated to adhere to stringent industry standards established by various organisations, such as TIA, ISO, and IEC. One-cord referencing seamlessly aligns with these requirements by reducing variables within the testing process. With a diminished number of connection points, reference loss measurements attain greater accuracy and consistency, ensuring that networks meet industry benchmarks.

Substantial Cost Savings:

In data centres where time is a valuable resource, one-cord referencing offers significant efficiency gains. By eliminating the need to modify test setups when switching between connector types, technicians can expedite certification processes and swiftly progress to subsequent tasks, thereby accelerating overall deployment schedules.

Enhanced Accuracy and Consistency

Each additional cord or adapter within a test setup carries the potential to introduce errors. One-cord referencing results in more consistent and reproducible outcomes by reducing the number of connection points. This accuracy is paramount in high-performance data centres where even minute signal loss can impact operational efficiency.

Simplified Learning Process

One-cord referencing simplifies the learning process for technicians new to fibre testing. With fewer components and steps to manage, teams can concentrate on comprehending test results rather than overseeing test setups, facilitating their rapid development into proficient professionals.

 

The VSFF Testing Breakthrough

The capability to execute one-cord referencing for duplex cables, including uniboot and Very Small Form Factor (VSFF) connectors, represents a significant advancement in the industry. This feature instills confidence in data centre managers when they verify and adopt VSFF technology that caters to high-density fibre requirements.

Technicians equipped with cutting-edge Optical Loss Test Sets (OLTS) specifically designed for one-cord referencing gain a competitive advantage. They can provide comprehensive testing and certification for VSFF and other high-density connectors. This expertise not only expedites testing but also presents opportunities to generate revenue through faster and more accurate fibre setups.

The Next Iteration of Fibre Testing Is Here

As networks evolve towards increased speed and complexity, it is imperative to update our testing methodologies. One-cord referencing is not merely a fleeting trend; it represents a substantial advancement in fibre testing. It empowers technicians, regardless of their level of experience, to conduct more tests and achieve greater proficiency.

The most recent Optical Loss Test Sets (OLTS) designed for one-cord referencing feature impressive capabilities, enabling simultaneous measurement of loss, length, and polarity at multiple wavelengths within a fraction of a second.

EXFO’s PXM/LXM OLTS Technology

EXFO’s groundbreaking PXM/LXM Optical Loss Test Set (OLTS) significantly enhances Tier-1 fibre certification through its innovative one-cord referencing technology.

The Evolution of Fibre Testing Challenges

Modern data centres demand high accuracy during deployment. The proliferation of connector types, including VSFF, has rendered traditional testing methods cumbersome and prone to errors. These outdated tools often fail to adhere to industry standards, hindering deployment schedules.

Tier-1 Fibre Certification Fundamentals

Before exploring the benefits of one-cord referencing, it is essential to understand the core requirements of Tier-1 certification. During certification, technicians evaluate three critical factors:

  1. Insertion Loss: Quantifying the signal degradation as light traverses fibre connections.
  2. Length: Verifying the total fibre span to ensure proper installation and maintain signal strength.
  3. Polarity: Ensuring that fibres are mapped correctly to deliver signals to their intended destinations.

These assessments guarantee network functionality and compliance with industry regulations established by organisations such as TIA, ISO, and IEC.

 

One-Cord Referencing: A Revolutionary Approach

EXFO’s PXM/LXM OLTS Technology introduces a novel approach that transforms network testing.

The one-cord reference method significantly impacts traditional multi-cord approaches. This technique utilises a single cord to manage both transmit (TX) and receive (RX) paths in a duplex cable, simplifying the testing process substantially.

Key Benefits of One-Cord Referencing

Standards Compliance Without Compromise:

One-cord referencing aligns with industry standards by reducing variables introduced by multiple cords and adapters. This approach provides more consistent measurements, meeting TIA’s requirements for precise certification practices.

Significant Cost Savings:

In data centre setups with thousands of connections requiring testing, each minute saved translates into substantial cost reductions. Traditional methods often necessitate numerous cords and frequent connector type changes. One-cord referencing eliminates these additional elements, enabling technicians to complete certification tasks more efficiently.

Enhanced Accuracy and Consistency:

Each additional connection point in a test setup introduces potential variables and errors. By reducing connections through one-cord referencing, technicians obtain more stable results with a reduced likelihood of measurement discrepancies.

Streamlined Learning Process:

For technicians unfamiliar with fibre testing, old multi-cord setups can appear daunting and prone to errors. One-cord referencing reduces complexity, allowing even less skilled staff to perform accurate certifications with confidence.

 

 

PXM/LXM: A New Era in Fibre Certification

EXFO introduced the professional version of the PXM/LXM OLTS in 2025, introducing a novel approach to Tier-1 fibre certification in data centre networks. This innovative tool addresses the challenges of duplex and multi-fibre testing with unparalleled speed and flexibility.

Standout Features of the PXM/LXM System

Lightning-Fast Testing

The PXM/LXM has an impact on testing speed. It checks loss, length, and polarity on duplex and multi-fibre links at two wavelengths in one second—making the certification process much quicker than older methods.

Works with Many Connectors

EXFO's Click-Out adapters protected by patents, allow technicians to switch between different connector types in a matter of seconds. The system supports many connectors including duplex MDC, SN LC as well as MPO and SYSTIMAX MTP. This gives users the flexibility to adapt as connector technologies change in the future.

Advanced Polarity Validation

The PXM/LXM has a unique ability to find duplex and multi-fibre polarity problems hidden in trunk cabling. This ensures correct fibre connections before networks start operating. This approach gets things right the first time, which eliminates the need for costly fixes and problem-solving later.

Simplified Standards Compliance

EXFO's Click-Out adapters allow users to reference one cord for both duplex and multi-fibre cabling. This removes the need to use adapter cords that match pinned and unpinned gender types helping users to comply with TIA, ISO, and IEC standards without hassle.

Making VSFF Testing Easier in Crowded Spaces

The PXM/LXM OLTS device offers a comprehensive solution for VSFF testing, enabling data centre operators to reference a single cord for all duplex cables, including uniboot and Very Small Form Factor (VSFF) connectors. This significant advancement empowers operators to adopt and verify VSFF technologies with confidence, ensuring that their networks meet the evolving demands of high-density environments.

 

Maximise your advantage: EXFO’s PXM/LXM OLTS and FIP-500 Inspection Scope

Contractors equipped with EXFO’s PXM/LXM OLTS and tools such as the FIP-500 inspection scope gain a competitive edge in the market. These comprehensive testing services cater to new connector technologies, expediting testing processes and facilitating the expansion of business opportunities. EXFO’s solutions contribute to the rapid development and deployment of robust data centre systems that can effectively meet the challenges of tomorrow’s digital landscape.

 

PXM/LXM System’s Accurate and Efficient Certification

EXFO’s PXM/LXM system empowers technicians at all levels to achieve high accuracy and speed in the certification process. By simplifying testing procedures, the system enables companies to focus on the critical aspects of building robust and forward-looking data centre systems that can effectively accommodate the evolving needs of the digital world.

For data centre operators and contractors seeking to enhance their fibre certification processes, tools that enable one-cord referencing, such as EXFO’s PXM/LXM OLTS, are not merely novel equipment. These tools provide a competitive advantage in an increasingly competitive market.