NetSim Network Emulator

NetSim Network Emulator enables users to connect NetSim simulator to real hardware running live applications ( Video, Voice, File Transfer, Email, etc.). This is also termed as System-in-the-Loop (SITL). With NetSim emulator physical hardware and a simulation can interact as a unified system.

As shown in the figure above the configuration is real-sim-real with simulation sync’ed to wall clock. The simulation is used as a transit network in which datagrams experience simulated network effects.

NetSim Network Emulator can be used for various purposes:

• Testing application performance subject to network effects such as error, delay, loss, etc.
• Impact is immediately apparent with no need to interpret from simulation statistics
• R & D in new protocol design. Test your protocol performance with real applications.
• Design state testing before the real devices/software are ready
• Integration into cyber test beds

NetSim Network Emulator is a cost-effective alternative to hardware emulators that have high costs, complicated configuration requirements and limited scale

Example use case for Military Radios

• Scenario of soldiers communicating as a Mobile Ad-hoc Network (MANET) using UHF/VHF radios created in NetSim emulation server
• Each soldier is emulated by a virtual machine created inside physical server The MANET scenario in NetSim covers parameters for mobility, RF propagation losses, L3 / MAC / PHY protocol attributes etc.
• Real-time traffic such as data, voice or video can be sent between the VM's i.e. from one soldier to another
• Output metrics such as loss, delay, error, throughput, quality of service etc. can be measured Different "What-if" scenarios can be played

Example use case for 5G Networks

• A typical 5G network. Cameras uploading video and phones (UEs) uploading and downloading files.
• Change network parameters such as bandwidth, pathloss, transmit power, antenna count, mobility etc.
• Run various what-if scenarios by modifying the file transfer and video rates
• Study application performance and analyze metrics such as loss, delay, error, throughput, quality of service etc.

Features and Specifications

• NetSim is an IP-based, data plane, flow-through network emulator that processes actual data between clients and servers through a virtual network infrastructure.
• The setup requires a dedicated system running NetSim (Windows 10/11), connected via L2 switch to the servers/PCs running your applications, with the NetSim system set as the gateway.
• NetSim creates a virtual network where real devices are mapped to virtual equivalents, allowing traffic to flow through the emulator and experience configured network conditions (delay, loss, error).
• The emulator supports "what-if" scenario analysis by allowing modification of network settings between runs and providing performance metrics for analysis.
• Traffic sources and destinations must both be in the real world (flowing through the emulator) or both in the virtual domain; a virtual node cannot be a sink for real traffic and vice versa.
• NetSim converts real packets to virtual NetSim packets at ingress, applies network effects, then converts back to real packets at egress.
• Current technical constraints include a 20ms resolution for packet latency (which may impact ack-based protocols)
• The emulator simulates generic network devices rather than vendor-specific equipment, and provides PCAP capture capability for virtual router traffic.
• NetSim provides standard socket-based connectivity rather than specific physical interfaces (like LTE) for device testing.
• This information describes our Commercial Off-The-Shelf (COTS) version; custom development is available to address specific requirements beyond these capabilities.