Insider Brief
- Cisco introduced two research prototypes designed to coordinate quantum networks and help applications use connected quantum devices without configuring each component individually.
- The Quantum Network Controller manages hardware, schedules connections and monitors their quality, while the updated Network-Aware Quantum Compiler divides computing tasks among processors and requests the necessary network resources.
- Cisco reported that its software coordinated equipment from multiple vendors across about 11 miles of commercial fiber in New York City, achieving greater than 99% polarization fidelity at room temperature.
Cisco has introduced two research prototypes designed to coordinate quantum networks, aiming to make connected quantum machines easier to operate and use.
The company’s Quantum Network Controller and updated Network-Aware Quantum Compiler address different parts of that task. The controller coordinates the hardware needed to supply quantum connections, while the compiler determines how a quantum program should be divided among processors and what connections it needs, according to a Cisco blog post by Vijoy Pandey, senior vice president of Outshift by Cisco.
The broader goal is to let applications request a quantum networking service without requiring operators to configure every device and connection individually. An application, for example, would specify which endpoints it needs to connect, the quality and rate of the connection, and when it should be available. Software would then arrange and maintain the service.
Cisco describes both systems as research prototypes. The announcement outlines an approach to operating larger quantum networks, but it does not establish that a large network of connected quantum processors is ready for commercial use.
One of the challenges is that a single processor has limited capacity, and connecting processors could provide another route to larger systems. Those connections, however, require more than a physical link. They also need software that can allocate resources, coordinate precise timing and respond when an operation fails.
From Individual Links to a Shared Network
Quantum networks can link quantum devices so they can work together, even when they are in different locations. These connections could help quantum computers share tasks and support new tools for secure communications and more precise measurements.
In Cisco‘s model, applications would request entanglement between specified endpoints rather than control the equipment that produces it. The request would include fidelity — a measure of how closely the delivered quantum state matches the intended state — along with the required rate and timing.
Pandey writes that the current operating burden is like driving a car while manually controlling its individual mechanical parts. He adds that quantum networking needs an interface that lets users specify an outcome while the underlying system handles the machinery.
Until now, quantum networks have largely been built one point-to-point connection at a time, according to the post. Hand-built software could manage networks with a handful of nodes, but that approach becomes harder as the number of devices and competing applications grows.
A fully connected network of 1,000 nodes would require nearly 500,000 dedicated links if every pair had its own connection. Cisco’s proposal is to create a shared switching system through which each node could reach the others.
Earlier this year, the company introduced its Universal Quantum Switch, another prototype to support shared connectivity among different types of quantum systems.
The controller is meant to supply the operating layer above that switch. It would decide which connections to establish, which applications receive entanglement, what quality they need and when the resources should be available.
Those decisions can become more demanding when multiple applications share equipment. A network must coordinate requests while meeting the timing requirements of quantum operations, rather than simply establish a connection and leave it running.
Delivering Entanglement on Demand
Cisco calls its proposed service model Entanglement-as-a-Service. The idea is to make entanglement a resource that applications request and the network schedules, similar to the way cloud services allocate computing capacity.
The Quantum Network Controller provides interfaces for categories of equipment, including sources, switches, detectors and timing systems. Beneath those interfaces sits a hardware abstraction layer — or, software that translates common instructions into the commands needed by specific devices.
That structure is intended to reduce the amount of hardware-specific work required by applications and operators. Equipment from different vendors could connect through the same category of interface, according to Pandey.
The post identifies Qunnect, based in Brooklyn, and Swabian Instruments among the vendors whose hardware can work through this approach. The equipment includes sources, switches and time taggers, devices that record when detection events occur.
Maintaining a quantum connection also presents a monitoring problem. Measurements can disturb quantum states, so operators cannot inspect quantum information in the same way conventional networking tools examine ordinary data traffic.
Cisco reports the controller instead checks link quality statistically. When performance deteriorates, it applies predefined responses such as tuning equipment, retrying an operation or reinitializing a device. It calls for human intervention when those measures fail.
The controller is also designed to continue checking a connection while an application uses it and release the hardware when the task is over. In a shared network, equipment that is tied up by one completed job might be unavailable for another.
Pandey points to a February 2026 deployment as evidence that Cisco software can coordinate equipment from multiple vendors outside a laboratory setting.
According to the post, the software coordinated multi-node entanglement distribution and swapping across 17.6 kilometers, or about 11 miles, of deployed commercial telecommunications fiber in New York City. Entanglement swapping is a process used to extend entanglement across separate links.
Cisco reported greater than 99% polarization fidelity at room temperature. Polarization is a property of light used to represent quantum information in some systems.
Connecting Programs to Network Resources
The updated Network-Aware Quantum Compiler addresses the application side of the problem.
A compiler translates a program into instructions that computing hardware can execute. Cisco’s compiler also considers how to divide a quantum program among separate processors and what network resources that division requires.
It determines which nodes need entanglement, how much they need and the required fidelity, then turns those decisions into requests to the controller.
The two systems have distinct responsibilities. The compiler plans the computation and its networking needs. The controller coordinates the hardware to supply the requested service.
Cisco says its compiler receives no special access to the controller. It uses a general-purpose interface that is also intended to support third-party compilers and other applications.
That design would provide a common interface that allows application developers to request network services without building their software around one particular collection of quantum devices.
Computing is only one proposed use, according to the post. Pandey writes that security and coordination applications called Quantum Alert and Quantum Sync are designed to request entanglement through the same interface, with sensing applications expected to follow.
The architecture therefore treats quantum networking as shared infrastructure for several types of workloads. Its value would depend on whether the system can satisfy different requests reliably while coordinating limited hardware resources.
Looking ahead, Pandey writes: “The Cisco Universal Quantum Switch made it physically possible to route quantum information between devices that speak different languages. Our Controller makes it operationally possible to decide, continuously, which of those routes gets built, for whom, and when. 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.”
