GNS3 vs QuNetSim

GNS3 is free, open-source software for emulating, configuring, testing, and troubleshooting virtual and real networks. Its graphical client works with a virtual machine, and servers can run locally or remotely. Users can combine emulated devices running actual images with simulated devices, including a built-in layer 2 switch. It supports appliances from vendors such as Cisco, Brocade, Cumulus Linux, and HPE, as well as Docker, QEMU-based appliances, VMware, VirtualBox, Hyper-V, and connections to real networks. The GNS3 Marketplace offers preconfigured appliance templates with recommended settings. It runs on Windows, macOS, and Linux; documentation recommends the GNS3 VM for most Windows and macOS setups and complex topologies. Users must supply their own Cisco IOS images. There are no monthly or yearly license fees, and device capacity depends in practice on the host computer’s CPU and memory. GNS3 is used for networking education, certification practice, proofs of concept, demonstrations, and interoperability testing. A server has no authentication enabled by default and should be restricted at the network level.

QuNetSim is a free, MIT-licensed Python framework for developing and testing quantum networking applications and protocols. It includes built-in exercises for qubit teleportation, entanglement distribution, superdense coding, and quantum key distribution. Multi-hop networks use entanglement swapping to create links between distant hosts. You can define routing functions from classical and quantum network states, represented with NetworkX graphs. The event-driven model gives packets sequence numbers and lets them wait for acknowledgements. Host, Protocols, and Network components correspond to application, transport, and network layers. Supported backends include SimulaQron, ProjectQ, and EQSN, with SimulaQron listed as the default; custom network and qubit backends can also be imported. Installation uses pip and includes an example-generating template. Linux, macOS, and Windows setup instructions require Python 3.5 or newer. It is intended for students and instructors, especially newcomers, and is described as educational rather than a full quantum-physics simulator.