AI infrastructure limits are shifting from compute to networking, as fiber capacity becomes critical to data center scale.
Meta has announced a $6 billion, multi-year fiber supply agreement with Corning, highlighting how AI infrastructure constraints are shifting beyond compute and into the physical network.
Under the agreement, Corning will supply Meta with optical fiber, cable, and connectivity solutions to “accelerate the buildout of the most advanced data centers in the United States to support Meta’s apps, technologies, and AI ambitions,” the companies said in a statement.
As hyperscalers race to build ever-larger AI clusters, warnings from companies like Microsoft about a looming “networking wall” are shifting attention to physical network capacity, especially fiber, as a limiting factor in AI data center growth.
So far, much of the AI infrastructure debate has focused on access to factors like GPUs and power. But the explosive east-west traffic generated by large AI models is pushing data center networks to their physical limits, forcing cloud providers to reconsider their options.
“While GPUs, power, and cooling have long been recognized as essential constraints for data center scaling, fiber, which was once seen primarily as a commodity, is assuming a strategic role of its own,” said Shriya Mehrotra, director analyst at Gartner.
Mehrotra added that as hyperscalers lock in long-term fiber supply and pour investment into dedicated connectivity, competition for capacity is intensifying. That, in turn, is tightening availability for other enterprises and extending deployment timelines.
The role of fiber in AI scaling
As AI systems scale, limits in networking are increasingly holding back performance, leaving costly GPUs underused and reducing the payoff from large infrastructure investments.
Manish Rawat, a semiconductor analyst at TechInsights, pointed out that optical fiber is now emerging as the next structural constraint on AI scaling with potentially long-term implications.
“Fiber is the silent dependency that scales non-linearly with AI growth,” Rawat said. “AI workloads generate massive east-west traffic, requiring tight synchronization across thousands of GPUs, which sharply increases intra-data-center and inter-campus optical demand.”
But the so-called networking wall is not a single bottleneck, according to Sanchit Vir Gogia, chief analyst at Greyhound Research.
“It’s an overlapping set of constraints that surface when AI workloads hit scale, spanning fiber availability, switching density, optical transceiver limits, and architectural inefficiencies,” Gogia said.
The combined stress of AI scale and concurrent government broadband rollouts has snapped the historical assumption that fiber is abundant and cheap, Gogia added.
However, simply deploying more fiber will not be sufficient to address the challenge, analysts said. The underlying network architecture should improve as well.
“Beyond raw fiber and switching, the overall network architecture must evolve to efficiently route, process, and manage AI-generated traffic,” Mehrotra said. “Existing designs may not be suitable for the aggregated and bursty traffic patterns generated by massive AI deployments, necessitating new architectures such as AI network fabrics and optimized data center interconnect solutions.”
Shift in data center strategy
Rawat noted that the Meta-Corning deal is not aimed at solving short-term fiber shortages, but at giving Meta greater certainty and control as it builds AI infrastructure at scale.
“Meta is locking in guaranteed optical capacity, manufacturing priority during AI build cycles, and fiber designs tailored to its architectures, while insulating supply from geopolitical risk,” Rawat said. “It follows the same vertical integration playbook hyperscalers used for custom AI chips, power contracts, and grid planning. Fiber is simply the next layer.”
This approach, Rawat said, is accelerating the emergence of a two-tier networking ecosystem, with hyperscalers operating tightly controlled supply chains while enterprises depend on shared capacity with longer lead times and fewer customization options.
“The model shifts from ‘buying fiber’ to ‘securing fiber’ via forward agreements, standardization, and multi-year planning,” Rawat said. “Cloud interconnect pricing will stay firm as hyperscalers absorb surplus capacity. Ultimately, network architecture choices will matter more than vendor selection for enterprises seeking resilience and scalability.” Hyperscalers are effectively moving from being tenants in the fiber ecosystem to strategic owners, according to Gogia. “What used to be bought on the spot market is now being locked in years ahead to secure cost certainty, deployment speed, and operational control as AI infrastructure becomes increasingly capital-intensive,” Gogia added.
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