Tim Doiron, VP Solution Marketing at Infinera, explores why managed optical fiber networks could be the key to powering today’s bandwidth-hungry data centre boom.

Managed optical fiber networks (MOFNs) play an increasingly important role for communication service providers (CSPs) in meeting the bandwidth demands of internet content providers (ICPs). 

The expanding deployment of power-hungry GPUs that underpin AI with applications like ChatGPT and Copilot has sparked a global data centre construction boom, with the number of data centres expected to double in the next few years. 

But data centers don’t exist in isolation. They are linked via high-speed optical connectivity to other data centres and internet exchange locations, enabling geographical redundancy while also sharing workloads, storage, and increasingly, responding to generative AI queries. So, what is a MOFN, how does it differ from a traditional optical networking approach, and why is it happening?

Traditional managed bandwidth

To understand MOFNs, let’s first review traditional optical transport networks and service delivery. 

As depicted in Figure 1, a CSP invests in trenching optical fibres and installs optical line system equipment to enable wavelengths to ingress and egress the fibre and coherent optical engines to light the fibre – like today’s 1.2+ Tb/s-per-wavelength transponder sleds or 800 Gb/s multi-haul coherent pluggables. The CSP then offers transport services over this shared infrastructure to any customer that may need them, including enterprises and ICPs. 

As an example, one can lease one or multiple 100 Gb/s or 400 Gb/s transport services across a metro, a continent, or even an ocean in the case of submarine networks. The enterprise or ICP pays a monthly recurring fee to the CSP for the capacity of the transport service provided and the service-level agreement (SLA) associated with the service.

Big capacity driving private builds

There are, however, instances where an enterprise or ICP needs significant amounts of connectivity – say enough to consume the capacity of one or multiple fibre pairs – delivering multiple tens of terabits per second. In such instances, the enterprise or ICP may choose to build and manage its own private optical transport network. This usually involves leasing dark fibre from a CSP like Arelion, Exa, Lumen Zayo, or other dark fibre wholesale provider. The enterprise or ICP then assumes the responsibility for acquiring, installing, and managing the optical line system and optical engine equipment. In short, they take on the responsibilities of the service provider for the reliable transport of their network traffic.

Bring on the MOFNs

That brings us to MOFNs. As also depicted in Figure 1, a MOFN sits architecturally and commercially between the traditional managed bandwidth approach and the dark fibre private-build approach. 

MOFNs involve high-capacity networks and the close collaboration of a CSP, an ICP, and an optical vendor with extensive ICP and data centre interconnect experience and technology. 

The primary driver for MOFNs is the growing number of data centres and the need for high-speed interconnectivity among them. While data centre growth is a global phenomenon, we see particular acceleration in India and throughout Asia, the Middle East, and parts of Africa. 

With more than 90 new submarine cables planned for deployment globally in the next few years, MOFNs also play a key role in the backhaul portion of submarine networks – connecting submarine cable landing station traffic to data centres that may be hundreds or even thousands of kilometers away.

But if ICPs need high-capacity connectivity among data centres, why don’t they just light up dark fibre and create a private network? There are three key reasons: 1) regulation, 2) resources, and 3) risk. 

In some geographies, such as India, regulatory requirements may prevent ICPs from performing as a transport network operator. In other cases, an ICP may lack the right resources or qualified optical networking personnel to take on the added responsibility of running an optical transport network. Additionally, an ICP may be entering a new market or a new country and may want to reduce its risk by leveraging the skills, experience, and relationships of an in-country incumbent service provider. But the ICP would still want to influence the network design, and the type of optical equipment deployed.

Right capacity, right architecture, right solution

With MOFNs, the ICP directs the network architecture and vendor preferences for the optical line system and optical engine technology. With new data centre construction, it’s critical that server, storage, and compute equipment be installed and activated at just the right time. 

It’s equally critical that data centre interconnect capacity is delivered right on time for the data centre to go live. Given the highly engaged three-way relationship among ICP, CSP, and vendors in MOFNs, the benefit for the ICP is that it receives the right capacity from its preferred DCI vendor when and where it is needed, and at an economic value that meets its business objectives. The CSP in turn utilises its networking skills and expertise to grow its ICP business with a reliable recurring revenue stream while leveraging the latest DCI vendor solutions.

While we have treated MOFNs as one size fits all, it is worth noting that MOFNs do come in different shapes and sizes depending upon the network and the participants. In addition to what is outlined in Figure 1, there are variations to this model including a hybrid approach where the CSP builds a dedicated optical line system and the ICP deploys its own optical engine technology over the top. 

In all MOFN cases, an ICP, CSP, and leading DCI vendor collaborate to meet the ICP’s architectural, technology, and business objectives.

Wrapping up MOFNs

MOFNs represent a significant evolution in the way ICPs and CSPs collaborate to meet the growing demands for high-capacity optical transport. As data centres continue to proliferate globally, driven by the increasing deployment of AI applications and the need for geographical redundancy, MOFNs offer a flexible and efficient solution. 

By leveraging the expertise of CSPs and the technological advancements of optical vendors, ICPs can achieve the right capacity, architecture, and economic value to support their business objectives. This collaborative approach not only ensures timely and reliable connectivity but also mitigates the risks associated with private network builds. 

As the digital landscape continues to evolve, MOFNs will play a crucial role in enabling seamless and scalable connectivity for the future.