Adrian Lita
Network Topology Simulator (nt-sim)
Key Highlights
- O-RAN support
- Proprietary models
- IETF standards
Overview
The Network Topology Simulator (nt-sim) is a sophisticated Python-based simulation platform designed to emulate complex telecommunications network topologies. It supports both industry-standard O-RAN (Open Radio Access Network) specifications and proprietary vendor models, enabling comprehensive testing of network management systems without requiring physical hardware infrastructure.
Technical Details
Built using Python 3.8+, the simulator leverages libyang for YANG model parsing, sysrepo as the datastore implementation, and netopeer2 for NETCONF protocol handling. The architecture uses Docker containerization to isolate each simulated network element, allowing hundreds of virtual devices to run concurrently on standard hardware. Each container runs a full NETCONF server with configurable YANG models, supporting both configuration and operational data. The system implements efficient resource sharing, with a central orchestrator managing container lifecycle and network topology configuration.
Challenges Overcome
- • Scaling to simulate hundreds of network elements on limited hardware resources
- • Maintaining accurate timing and synchronization across simulated devices
- • Supporting multiple conflicting YANG model versions simultaneously
- • Implementing realistic network behavior including failures and degradation
- • Ensuring O-RAN specification compliance across diverse models
- • Optimizing Docker container startup time for rapid testing cycles
Outcomes & Impact
- ✓ Reduced testing costs by 80% compared to physical lab setups
- ✓ Enabled continuous integration testing of network orchestration systems
- ✓ Used by multiple telecommunications companies for pre-deployment validation
- ✓ Facilitated training programs for network management software
- ✓ Accelerated development cycles by providing instant test environments
