Chapter 12: Connectors, Cables & Network Infrastructure

12.1 Overview

An NVIDIA GB200 NVL72 rack uses 5,184 copper cables. A single AI data center campus with hundreds of thousands of GPUs requires millions of connectors, tens of millions of meters of fiber optic cable, and thousands of power cable assemblies. This chapter covers the physical layer that ties together the silicon described in Chapters 06-10, the optics described in Chapter 11, and the power systems described in Chapters 13-14. These are the screws and bolts of the AI buildout: unglamorous, low-margin compared to semiconductors, but absolutely essential and increasingly constrained.

The connector and cable market splits into three categories for AI data center purposes. The first is high-speed signal interconnects: the copper and fiber cables plus their mating connectors that carry data between GPUs, between servers, and between racks. This includes DAC (Direct Attach Copper) cables, AEC (Active Electrical Cable) assemblies (see Chapter 10 for Credo’s role), fiber optic patch cords, and the board-level connectors (sockets, mezzanines, backplane connectors) inside servers. The second is power interconnects: the cables, busbars, and connectors that deliver electrical power from the facility to the rack, from the rack to the server, and from the server to the GPU. As rack power densities climb past 100 kW toward 200-500 kW, power delivery becomes a critical design constraint. The third is fiber optic cable: the physical glass fiber manufactured by companies like Corning and Prysmian that provides the transmission medium for optical transceivers.

Amphenol has emerged as the dominant force in AI data center interconnects. The company overtook TE Connectivity in 2025 to become the world’s largest connector company, with FY2025 revenue of $23.1 billion, up 52% year-over-year. Its IT Datacom segment surged from $3.65 billion (24% of sales) in 2024 to $8.31 billion (36% of sales) in 2025. Amphenol custom-engineered the NVLink spine cartridge for NVIDIA’s GB200 NVL72 system and holds an estimated 33% share of the AI datacom connector segment. The company is also acquiring CommScope’s Connectivity and Cable Solutions business for $10.5 billion, which will add approximately $4.1 billion in annual sales and expand its fiber optic infrastructure portfolio ¹²³.

TE Connectivity remains the second-largest connector maker globally, with deep expertise in high-speed signal integrity, power connectors, and thermal solutions for data centers. TE’s AdrenaLINE product family targets 224G per-lane connectivity, and the company is developing 448G co-packaged copper connectors for next-generation AI systems. TE’s FY2025 revenue grew 8.9% year-over-year, a solid result but far behind Amphenol’s 52% surge, reflecting TE’s greater diversification across automotive and industrial markets ⁴⁵.

Corning’s role in the AI buildout has been transformed by a single deal: Meta’s up to $6 billion multi-year agreement for fiber optic cable and connectivity solutions, announced in January 2026. This is the largest fiber optic supply deal in history. Corning’s optical communications revenue jumped 33% in Q3 2025 to $1.65 billion, and full-year 2025 revenue reached $15.63 billion. Enterprise optical sales surged 58% in Q3, driven by AI product adoption. AI data centers require 10-36x more fiber than traditional CPU-based setups, and Corning’s fiber inventory is sold out through 2026. The company is expanding its Hickory, North Carolina facility to meet demand from NVIDIA, Meta, Google, Amazon, Microsoft, and OpenAI ⁶⁷⁸.

The private side of this market includes Molex (owned by Koch Industries), Samtec, and Luxshare (China). Molex generates approximately $6 billion in annual revenue and is collaborating with Samtec on next-generation twinax flyover cable systems for data centers. Samtec is a specialist in high-speed board-to-board and cable interconnects, providing Si-Fly HD products for AI/ML workloads. Prysmian, the world’s largest cable company, has partnered with Relativity Networks for hollow-core fiber optic cable production targeting data center applications ⁹¹⁰¹¹.

12.2 Market Sizing & Growth

Global connector market: Market sizing varies by source. One estimate places the market at $73 billion (2025) growing to $100 billion by 2034 at 3.2% CAGR ¹²; another estimates $88.7 billion (2024) growing to $173.4 billion by 2035 at 6.27% CAGR. The discrepancy reflects scope definition differences (cables vs. connectors-only, industrial vs. electronic). Regardless of the total market definition, the AI-relevant high-speed interconnect segment is growing far faster than the overall market.

Fiber optic connector market: Projected to grow from $6.42 billion in 2025 to $13.86 billion by 2034 at an 8.9% CAGR, directly fueled by cloud computing and AI workload demand ³. Amphenol’s own AI-related connector revenue growth (IT Datacom +128% YoY) substantially outpaces these projections, suggesting the AI segment within the connector TAM is growing 10-15x faster than the overall market.

Relative to the $725B capex framework (see Section 1.2), connectors, cables, and passive interconnects represent approximately 2-4% of total AI infrastructure spending. However, each NVL72 rack requires 5,184 individual copper cables, making connectors a high-volume, high-complexity deployment challenge even at low unit cost. The bottleneck in this layer is not price or scarcity but deployment logistics and qualification speed.

DAC/AOC market: Projected to grow from $2.7 billion to $10.7 billion by 2034, reflecting the massive cabling requirements of GPU clusters ².

Amphenol: FY2025 revenue $23.1 billion (+52% YoY). IT Datacom revenue $8.31 billion (+128% YoY). Communication Solutions division revenue +91% YoY. Q3 2025 revenue $6.2 billion (+53% YoY). CommScope CCS acquisition ($10.5 billion) pending first half 2026 ¹³.

TE Connectivity: FY2025 revenue grew 8.9% YoY. Industrial Solutions segment revenue surged 74.6% YoY in Q2 2025, driven by AI infrastructure demand. AdrenaLINE 224G platform shipping. Developing 448G co-packaged copper connectors ⁴⁵.

Corning: FY2025 total revenue $15.63 billion. Optical communications revenue +33% in Q3 (to $1.65 billion). Enterprise optical sales +58% in Q3. Meta deal up to $6 billion. Springboard plan targets $11 billion in incremental annualized sales by end of 2028 ⁶⁷⁸.

Molex (Koch Industries): Approximately $6 billion annual revenue. 72 manufacturing facilities across 18 countries, ~42,000 employees. Not publicly traded. R&D ~5% of revenue, focusing on high-speed data transmission and miniaturization ⁹.

Prysmian: World’s largest cable manufacturer. Partnered with Relativity Networks for hollow-core fiber production for AI data centers. Hollow-core fiber travels 47% faster than standard glass fiber, enabling data centers to be located farther from power sources ¹¹.

12.3 Supply Chain Flowchart

CONNECTORS, CABLES & PASSIVE INTERCONNECTS
    |
    |---> HIGH-SPEED SIGNAL INTERCONNECTS (inside server / rack-to-rack)
    |    |
    |    |-- COPPER CABLES & ASSEMBLIES
    |    |    DAC (Direct Attach Copper): passive, <3m reach
    |    |    AEC (Active Electrical Cable): Credo (~88% share per 650 Group, Oct 2025)
    |    |         Astera Labs: Aries Smart Cable Modules (AEC + retimer)
    |    |         Montage Technology (China): PCIe 6.x/CXL 3.x AEC (Jan 2026)
    |    |         Market projected to hit $4B by 2028 (JPMorgan)
    |    |    NVLink copper cables: Amphenol (primary), TE (backup)
    |    |    Twinax flyover systems: Samtec + Molex (licensed collaboration)
    |    |
    |    |-- FIBER OPTIC CABLES
    |    |    Corning: dominant fiber manufacturer; $6B Meta deal
    |    |    Prysmian: world's largest cable company; hollow-core fiber R&D
    |    |    CommScope: fiber infrastructure (being acquired by Amphenol)
    |    |    Sumitomo Electric: fiber and cable
    |    |    OFS Fitel (Furukawa Electric): specialty fiber
    |    |
    |    |-- BOARD-LEVEL CONNECTORS (inside the server)
    |    |    Amphenol: GPU sockets, NVLink spine cartridges, backplane
    |    |    TE Connectivity: AdrenaLINE (224G), near-chip sockets, mezzanines
    |    |    Samtec: Si-Fly HD, Flyover cable systems, board-to-board
    |    |    Molex: BiPass systems, fiber optic connectors, Si-Fly (licensed)
    |    |    Foxconn/Hon Hai: high-density server connectors
    |    |    Luxshare (China): emerging high-speed connector supplier
    |    |
    |    +-- I/O CONNECTORS & PANELS (server faceplate)
    |         OSFP / OSFP-XD form factor: 800G/1.6T transceiver interface
    |         QSFP-DD: 400G/800G interface (being superseded by OSFP)
    |         Amphenol, TE, Molex: cage and connector assemblies
    |
    |---> POWER INTERCONNECTS (facility to chip)
    |    |
    |    |-- RACK-LEVEL POWER
    |    |    Busbars: Amphenol, TE, Eaton, Schneider
    |    |    Rack PDU connectors: Amphenol, TE, Molex
    |    |    HVDC distribution connectors: emerging standard (TE leading)
    |    |    Liquid-cooled busbars: TE (new product line for AI racks)
    |    |
    |    +-- SERVER-LEVEL POWER
    |         GPU power connectors: 12VHPWR / 12V-2x6 standard
    |         PCIe power cables: Amphenol, TE, Molex
    |         Custom power cable assemblies: server ODMs (Foxconn, Wiwynn)
    |
    +---> STRUCTURED CABLING (within data center facility)
         Corning: fiber backbone, Gen AI fiber-and-cable system
         CommScope (→ Amphenol): structured cabling systems
         Panduit: cable management, fiber and copper infrastructure
         Belden: enterprise networking cables
         Leviton: data center structured cabling

12.4 Key Companies

Company	Ticker	Exchange	Approx. Mkt Cap	Role in Buildout	Key Metric
Amphenol	APH	NYSE	~$158B	#1 connector company; NVLink cables, GPU sockets, high-speed I/O; acquiring CommScope CCS	FY2025 revenue $23.1B (+52%); IT Datacom $8.31B (+128%)
TE Connectivity	TEL	NYSE	~$50.0B	#2 connectors; AdrenaLINE 224G, power connectors, liquid-cooled busbars	FY2025 revenue +8.9% YoY; AI industrial segment +74.6%
Corning	GLW	NYSE	~$161B	Dominant optical fiber manufacturer; Gen AI fiber products	FY2025 revenue $15.63B; Optical comms +33%; $6B Meta deal
Prysmian	PRY	Milan	~$43.6B	World’s largest cable company; fiber optic, power cables, hollow-core fiber R&D	Partnered with Relativity Networks for hollow-core fiber
Molex (Koch Industries)	Private	Private	Private	~$6B revenue; high-speed connectors, fiber optic, BiPass systems	72 facilities, 42,000 employees; Si-Fly HD with Samtec
Samtec	Private	Private	Private	High-speed board-to-board, Flyover cable systems, mid-board optics	Key supplier for AI/ML and HPC interconnects
Luxshare Precision	002475	Shenzhen	~$30.0B	Chinese high-speed connector supplier; growing in server interconnects	Serving domestic and international hyperscaler supply chains
Belden	BDC	NYSE	~$5.0B	Enterprise networking cables, structured cabling	Traditional data center cabling, less AI-specific
CommScope (CCS)	Private	Being acquired	Private	Fiber infrastructure, structured cabling (being acquired by Amphenol for $10.5B)	~$4.1B annual sales; will become part of Amphenol

12.4.3 Inter-Data-Center Backbone (Submarine Cables, Long-Haul Fiber, WAN)

AI training clusters are growing beyond what a single data center can house. Multi-campus training runs require backbone connectivity between sites that, in some cases, exceeds anything previously built. Meta’s AI backbone at a single site pair is reportedly 2x the capacity of the entire global backbone built over the prior decade. The US needs a roughly 2x increase in fiber route miles by 2029 to support projected AI data center growth. NVIDIA’s $3.2 billion investment in Corning (May 2026) for optical fiber manufacturing signals how seriously the backbone constraint is being taken at the GPU level ¹⁴; see Chapter 11, Section 11.5 for full context.

Company	Ticker	Exchange	Approx. Mkt Cap	Role	Key Metric
Corning	GLW	NYSE	~$161B	Optical fiber manufacturer; dominant in data center fiber	NVIDIA $3.2B investment (May 2026). Meta $6B fiber deal (Jan 2026). Sold out through 2026. Expanding Hickory, NC.
Prysmian	PRY	Borsa Italiana	~$43.6B	World’s largest cable company; fiber optic and power cables	Acquired Encore Wire ($4.8B, 2024). Hollow-core fiber R&D with Relativity Networks.
SubCom	Private	Private (Cerberus)	Private	Submarine cable manufacturing and installation	One of three companies globally that can build subsea cable systems. Meta Project Waterworth ($10B+).
NEC	6701	TSE	~$40.0B	Submarine cable systems (NEC subsidiary)	Second-largest submarine cable manufacturer after SubCom. Major Pacific and Indian Ocean projects.
HMN Technologies	Private	Private (Hengtong)	Private	Submarine cable (formerly Huawei Marine)	Third major submarine cable manufacturer. Chinese ownership creates geopolitical complexity for Western routes.
Lumen Technologies	LUMN	NYSE	~$8.0B	Largest US dark fiber provider; long-haul terrestrial fiber	Operating ~500,000 route miles of fiber. AI-driven demand reviving a previously declining business.
Zayo Group	Private	Private (DigitalBridge)	Private	Dark fiber and network infrastructure	Major US/Europe fiber provider. Serves hyperscalers and enterprises.
Furukawa Electric	5801	TSE	~$5.0B	Optical fiber and cable manufacturing (Japan)	Major fiber producer alongside Sumitomo and Fujikura.
Sumitomo Electric	5802	TSE	~$59.0B	Optical fiber, InP substrates, power cables	Cross-layer company: fiber for interconnects, InP for photonics (Chapter 11), power cables.
Fujikura	5803	TSE	~$10.0B	Optical fiber and cable; fusion splicers	Japanese fiber manufacturer. Also makes fusion splicers used for fiber installation.
YOFC (Yangtze Optical Fibre)	6869	HKEX	~$44.9B	China’s largest optical fiber manufacturer	Dominant in Chinese domestic fiber market. Expanding internationally.

The submarine cable ecosystem is a natural oligopoly. Only three companies (SubCom, NEC, HMN Technologies) have the manufacturing capability, cable-laying ships, and deep-ocean installation expertise to build subsea systems. A single transoceanic cable project costs $300 million to $1 billion and takes 2-4 years from contract to completion. Hyperscalers (Google, Meta, Microsoft, Amazon) are increasingly building their own private submarine cables rather than leasing capacity on shared systems, which is driving a wave of new construction.

12.5 Bottleneck Analysis

Copper cable density per GPU rack (SEVERE): An NVL72 rack requires 5,184 copper cables. Scaling to 100,000 GPU clusters means millions of cable assemblies. The cable count creates physical constraints: cable management, airflow obstruction, weight, and installation labor. This is partly why the industry is pushing toward optical interconnects (Chapter 11) and co-packaged optics. But for the current generation of AI servers, copper cables remain essential for NVLink intra-rack connectivity, and Amphenol is the primary supplier ².

Fiber optic cable supply (SEVERE): Corning’s fiber inventory is sold out through 2026. AI data centers require 10-36x more fiber than traditional setups. The $6 billion Meta deal alone will absorb significant production capacity. Corning CEO Wendell Weeks confirmed the constraint on the Q4 2025 call: “If we could make more of these new products, we could sell more” ¹⁵. Corning is expanding its Hickory, NC facility and building three additional US plants (NVIDIA partnership), but new fiber manufacturing capacity takes 12-18 months to bring online. Meanwhile, every major hyperscaler (NVIDIA, Google, Amazon, Microsoft, OpenAI) is competing for the same fiber supply ⁶⁷.

NVLink connector sole-source (HIGH): Amphenol custom-engineered the NVLink spine cartridge connector for NVIDIA’s GB200 NVL72. TE Connectivity serves as a backup supplier. This is a design win that locks in Amphenol for the current generation and likely the next. If Amphenol experienced production disruptions, the GPU cluster buildout would slow. The connector is custom and cannot be sourced from generic suppliers ².

Power connector density (MODERATE-HIGH): As rack power densities climb from 40 kW (traditional) to 100-500 kW (AI), power delivery within the rack becomes a design-critical challenge. Higher currents require heavier-gauge conductors, larger connectors, and better thermal management. TE’s liquid-cooled busbar solutions and HVDC distribution connectors address this, but the transition from traditional AC power distribution to HVDC is still early-stage. A shortage of high-current power connectors could constrain the deployment of next-generation high-density racks ⁵.

Skilled installation labor (MODERATE): Unlike semiconductor chips, cables and connectors require physical installation by trained technicians. The sheer volume of connections per rack (thousands of cables, hundreds of connectors) means that data center construction timelines are partly gated by the availability of skilled cable installers. This bottleneck worsens as multiple hyperscalers compete for the same labor pool in the same geographic regions.

12.6 Risks

Copper-to-optical transition reduces copper cable demand: The long-term trend in data center interconnects is away from copper and toward fiber optics. Co-packaged optics (see Chapter 11) could eventually eliminate many of the copper cable runs inside a rack. If CPO scales faster than expected, companies heavily exposed to copper interconnects (Amphenol’s NVLink cable business, Credo’s AECs) could see demand plateaus sooner than projected. The counter-argument: the installed base of copper-based GPU systems (Hopper, Blackwell) will require copper cables for years, and new CPO systems still need copper for power delivery and short-reach PCIe connections.

Connector commoditization risk: High-speed connectors are increasingly specified by open standards (OCP, OSFP, QSFP-DD). As standards mature, the barrier to entry for additional connector suppliers falls. Chinese manufacturers like Luxshare are capable of producing high-quality connectors at lower cost. If hyperscalers qualify multiple sources for each connector type, pricing pressure on Amphenol and TE could intensify. So far, the rapid pace of generational change (56G to 112G to 224G per lane) favors incumbents who can engineer new solutions quickly, but this advantage diminishes as standards stabilize.

CommScope acquisition integration risk: Amphenol’s $10.5 billion CommScope CCS acquisition is transformative ³, adding approximately $4.1 billion in revenue and expanding its fiber optic infrastructure portfolio. But large acquisitions carry execution risk: customer overlap, organizational integration, and margin dilution. If the integration stumbles, Amphenol’s growth narrative weakens.

Corning cyclicality: Corning has experienced boom-bust cycles in fiber demand before (most notably during the dot-com era) ¹³. If AI capex slows or data center construction pauses, the company could face the same oversupply dynamic. The $6 billion Meta deal provides revenue visibility, but the broader market could soften. Corning’s diversification across display, automotive, and life sciences provides some buffer, but optical communications is now its largest and fastest-growing segment.

First principles check: Are cables and connectors really a bottleneck? Yes, at the physical level. Each connector in a high-speed signal path introduces insertion loss, return loss, and crosstalk. As data rates climb to 224 Gbps per lane, the engineering tolerances for connectors shrink to fractions of a decibel. A poorly performing connector can degrade an entire link and force the system to fall back to lower speeds or error correction, reducing effective throughput. The physics of signal integrity at these frequencies means that connector quality is not interchangeable. The vendor that solves signal integrity at 224G first wins multi-year design locks.