Cisco has built a Quantum Network Controller, a research prototype that lets an application ask a quantum network for entanglement and leaves the network to work out the delivery. Entanglement, a linked quantum state shared between distant points, is the resource these networks distribute, and operators today set up the hardware that produces it device by device, link by link.
Single quantum processors still hold fewer qubits than the work requires, so more capacity has to come from linking machines. Operators have built those links point to point, which has kept quantum networks to a handful of nodes. Anyone who wants a bigger network for computing, security, or sensing inherits a scheduling job too large to run by hand: who gets entanglement, at what quality, in what order, on what timing.
A thousand nodes wired point to point need close to 500,000 dedicated links. Cisco’s Universal Quantum Switch, a research prototype introduced earlier this year, is designed to replace those links with one shared fabric. The Controller is the software meant to schedule work across it.
What the controller does
The Controller offers one interface per device category (sources, switches, detectors, and timing systems) on top of a hardware abstraction layer, so vendors’ gear in the same category plugs in the same way. An application states the endpoints, rate, fidelity, and timing it needs, without knowing how the hardware produces the result. Cisco calls the model Entanglement-as-a-Service.
A quantum state cannot be read without destroying the information it carries, so the Controller cannot look inside traffic the way a classical monitoring tool can. It measures link quality statistically, applies predefined tuning, retries, or reinitialization when performance drifts, and escalates to a person only when that self-correction fails. It keeps checking the link while an application uses it and reclaims the hardware when the job ends.
What has been tested
In February 2026, Cisco software coordinated multi-node entanglement distribution and swapping with partner hardware over 17.6 kilometers (about 11 miles) of deployed commercial telecom fiber in New York City. Polarization fidelity, roughly how closely the delivered states matched the intended ones, came in above 99 percent, at room temperature. That run took place eight months before the Controller was introduced.
The compiler is the first customer
An updated Network-Aware Quantum Compiler is the Controller’s first native application. It splits a quantum program across processors, works out how much entanglement the network must deliver and between which nodes, and hands that request to the Controller. The Compiler gets no special access, so a third-party compiler would use the same interface. Security and coordination applications called Quantum Alert and Quantum Sync are designed to request entanglement the same way, and hardware from Brooklyn-based Qunnect and Swabian Instruments plugs in under the abstraction layer.
“Nobody has to keep a hand on every part anymore; we can now treat the quantum network as a system that delivers a service – whether it is to the application developer, to the operator, or to the hardware device vendor,” wrote Vijoy Pandey, senior vice president of Outshift by Cisco.
