Infrastructure for long-term growth
Organizations expanding AI environments, interconnecting data centers and building regional private networks need an infrastructure foundation that can scale without repeated redesigns. Spectrum Business Dark Fiber provides dedicated fiber infrastructure that supports evolving capacity demands while giving organizations greater control over their network architecture.
Dedicated infrastructure
Exclusive fiber resources help organizations maintain greater control over network architecture and long-term technology planning.
Capacity without rebuilds
Scale network capacity through optical technology upgrades instead of replacing physical infrastructure.
Resiliency by design
Meet availability and performance goals with engineered routes, physical diversity and flexible topology design.
Why choose Spectrum Business
Successfully deploying Dark Fiber requires more than available fiber assets. It takes experienced teams that can design, construct, deploy and support infrastructure at scale. Spectrum pairs dedicated fiber with the expertise to execute complex networking initiatives.
Dedicated project management
Single-point accountability from planning through deployment.
Engineering expertise
Route planning, resiliency design and infrastructure guidance.
Permit and construction support
Resources to help manage rights-of-way, local permitting and deployment challenges.
Full lifecycle support
Ongoing maintenance and restoration of the physical fiber infrastructure.
Extend your network to support your business needs
Wavelength Services
Dedicated 400G wavelength transport for AI training traffic, large-scale data movement and deterministic east-west performance between AI regions.
Dedicated Fiber Internet
Built for the bandwidth demands of AI-intensive operations nationwide with a 100% Uptime SLA guarantee.
Ethernet Services
Secure, high-speed multi-point connectivity between your distributed data centers, GPU clusters and locations — purpose-built for AI workload demands.
Cloud Connect
Direct, private access to leading hyperscale platforms. Your AI data stays off the public internet, end to end.
Award-winning performance
2026
Omdia Recognizes Spectrum Business as a Global Digital Fabric AI Pioneer
2026
A Notable vendor in Forrester’s The Secure Access Service Edge (SASE) Services Landscape, Q1 2026
2025
Top three ranked on the 2025 U.S. Fiber Lit Buildings LEADERBOARD, with the fastest lit building growth rate among the top three service providers over the past decade
2025
Leader in the Frost Radar™: Wavelength Services in North America, 2025
2025
Top three ranked provider on Vertical Systems Group 2025 U.S. Carrier Ethernet LEADERBOARD
2025
Leader in the Frost Radar™: Managed SD-WAN in North America, 2025
2026
Omdia Recognizes Spectrum Business as a Global Digital Fabric AI Pioneer
2026
A Notable vendor in Forrester’s The Secure Access Service Edge (SASE) Services Landscape, Q1 2026
2025
Top three ranked on the 2025 U.S. Fiber Lit Buildings LEADERBOARD, with the fastest lit building growth rate among the top three service providers over the past decade
2025
Leader in the Frost Radar™: Wavelength Services in North America, 2025
2025
Top three ranked provider on Vertical Systems Group 2025 U.S. Carrier Ethernet LEADERBOARD
2025
Leader in the Frost Radar™: Managed SD-WAN in North America, 2025
Speak with a specialist
Call us Monday-Friday, 8:00 a.m.-11:00 p.m. ET to speak with our U.S.-based team of sales specialists.
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U.S.-based specialists can help tailor a plan to your needs. Call or chat today to get started.
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Frequently asked questions
Dark fiber refers to unused or “unlit” fiber-optic cables that are installed but not currently connected to active network equipment. Essentially, it’s fiber infrastructure with no light signals transmitting data at the moment.
Dark fiber works by providing unused fiber-optic cables that organizations can "light" with their own equipment to create a private, dedicated network connection. Dark fiber is ideal for enterprises and carriers needing dedicated, high-performance networks with complete control over their connectivity.
Yes, dark fiber can be considered a telecommunications service, but it functions differently from traditional telecom services. Instead of providing active internet or voice services, dark fiber offers the physical fiber-optic infrastructure—unused fiber strands—that customers lease to create their own private, high-speed networks.
The difference between dark fiber and lit fiber comes down to who provides and manages the network service. Dark fiber refers to unused fiber-optic cable that is currently not carrying a signal. The customer leases the physical fiber and provides their own equipment to “light” it.
Lit fiber refers to fiber service that is already active and managed by the provider. The provider supplies the equipment, transmits the signal, and delivers a usable service.