Lease raw, unlit fiber strands across our expansive, privately owned network spanning California. Bring your own optics, light it your way, and scale to whatever capacity your business demands.
Single-mode
Dedicated strands
Your optics
Light it your way
Diverse paths
Route redundancy
Private
Physically isolated
Unlit · Customer-managed
5,000+
Route miles
∞
Capacity ceiling
24/7
Local NOC
Dark fiber hands you the physical layer and gets out of the way — the ultimate foundation for organizations that need to control everything.
Lease dedicated, unlit fiber strands across our network and run them as your own private infrastructure.
Bring your own optics and equipment. Choose your protocols, your capacity, and your upgrade path.
No imposed bandwidth ceiling. Scale to terabits by upgrading your own transceivers — not your contract.
A physically separate path with no shared electronics. Maximum control, security, and isolation.
Dark fiber is optical fiber that has been installed in the ground but is not yet "lit" by a provider's transmission electronics. The glass is there; the light is not. When you lease dark fiber from Vast Networks, you lease the physical strands themselves across our 5,000+ route miles of privately owned underground fiber in California — then light them with your own optics. The result is a private network you control end-to-end, with capacity and protocols that answer to you, not your carrier's product catalog.
With lit fiber, the provider owns the electronics on each end and delivers a managed circuit at a defined speed — simple and turnkey. With dark fiber, you own those electronics, which means you decide the bandwidth, the framing, and when to upgrade. Lit fiber is the right choice when you want a fully managed service; dark fiber is the right choice when you need maximum control, privacy, and a capacity ceiling limited only by your own hardware.
Because you supply the optics, the same pair of fibers can carry a few gigabits today and hundreds of gigabits — or terabits — tomorrow. Modern coherent and DWDM transceivers let you multiply capacity simply by swapping transponders, with no change to your underlying lease. That makes dark fiber uniquely future-proof: you grow on your own timeline, at the speed your technology allows, without renegotiating bandwidth every time demand spikes.
A dark fiber path is physically separate, with no shared provider electronics in line. Your traffic never mingles with anyone else's, and you can apply your own encryption and security policies across the entire route. For carriers, data centers, universities, hospitals, and organizations with strict compliance requirements, that physical isolation is often the deciding factor.
Dark fiber is built for organizations that want to operate like their own network. Carriers and wholesale providers use it to extend reach; data centers and cloud platforms use it for high-capacity interconnect; research universities, healthcare systems, and latency-sensitive trading operations use it for control and isolation. We design the path and monitor the physical plant 24/7 — you own everything that rides on top of it.
Common questions about leasing dark fiber, capacity, equipment, and availability.
Dark fiber is optical fiber that has been installed but is not "lit" by the provider's electronics. When you lease dark fiber from Vast Networks, you lease the physical glass itself and supply your own optics and equipment to light it — giving you a private network with capacity and protocols entirely under your control.
With lit (dedicated) fiber, we provide the transport electronics and deliver a managed service at a set speed. With dark fiber, you control the electronics on each end, so you decide the capacity, the protocols, and the upgrade path. Dark fiber offers maximum control and a near-unlimited capacity ceiling; lit fiber offers a fully managed, plug-and-play experience.
Because you own the optics, the ceiling is set by your equipment rather than your contract. With modern coherent and DWDM transceivers, a single dark fiber pair can carry hundreds of gigabits and scale into the terabits — and you can upgrade capacity simply by changing your own transponders.
Yes. Dark fiber is the physical layer only, so you provide and manage the optics and networking gear on each end. This is what gives dark fiber its flexibility and privacy. Our team can advise on path design and reach, and our NOC monitors the physical plant 24/7.
Dark fiber is a physically separate path with no shared electronics, which is why carriers, healthcare systems, research networks, and security-conscious enterprises choose it. Your traffic never traverses shared provider equipment, and you can apply your own encryption and security policies end-to-end.
We operate 5,000+ route miles of privately owned, underground fiber across California, with point-to-point, multi-site, and diverse/protected path options. Share your endpoints and routing requirements and we will map the available paths and provide a quote.
Tell us your endpoints and routing needs. We'll map available dark fiber paths and put together a quote.