Colloquium lecture: February 10, 2026, Niklas Hutt (tutor: Ottens)
Trace File Replay Module for ns-3
Network Simulations are essential for developing and evaluating communication protocols. With current developments such as large satellite constellations, simulations increasingly involve complex network topologies, leading to high computational cost. However, for many protocols it is sufficient to reproduce the end-to-end characteristics of a connection instead of explicitly simulating every network component.
This thesis presents the design and implementation of a trace-based replay module for the ns-3 network simulator that speeds up simulations by representing a complete multi-hop path between two nodes as a single dynamic link whose behavior is driven by externally recorded traces.
These traces capture time-varying end-to-end properties of the original network path, including propagation delay, bandwidth constraints, queue capacity, loss probability, and delay variation. By replaying these parameters, applications and transport protocols can be evaluated without explicitly simulating the full network topology.
A preliminary evaluation compares transport-layer metrics from full simulations and trace replay. The results indicate that trace replay effectively captures high-level transport dynamics, such as throughput and congestion window evolution. However, its accuracy for delay-sensitive metrics, like RTT, decreases as network complexity increases, while overall trends in congestion control and throughput remain preserved.
In summary, the trace replay module speeds up simulations while maintaining sufficient accuracy for comparative experiments, highlighting both its benefits and limitations and motivating further improvements in replay accuracy.
Time: 10:15 a.m.
Place: Room 04.137, Martensstr. 3, Erlangen
or
Zoom-Meeting:
https://fau.zoom-x.de/j/68350702053?pwd=UkF3aXY0QUdjeSsyR0tyRWtLQ0hYUT09
Meeting-ID: 683 5070 2053
Kenncode: 647333