1. Department of Telecommunications Split, September 2012 Improving distributed traffic generation performance by using IMUNES network emulator Valter Vasić, Mirko Sužnjević, Miljenko Mikuc, Maja Matijašević University of Zagreb, Faculty of Electrical Engineering and Computing Unska 3, Zagreb, Croatia mirko.suznjevic@fer.hr

2. Department of TelecommunicationsProblem  How to generate accurate network traffic in a scalable way?  User Behaviour Based Traffic Generator (UrBBaN-Gen)  Expandability  Virtualization  Virtualization technologies  Linux Containers (LXC, bridges) - current  IMUNES (FreeBSD jails, netgraph) - new  Results:  IMUNES outpreforms LXCs  Higher traffic loads on less hardware  Complex network arhitectures enabled Split, September 20122 /13

3. Department of TelecommunicationsOutline  Problem  Introduction  UrBBaN-Gen  IMUNES  Methodology  Results  Conclusion Split, September 20123 /13

4. Department of TelecommunicationsIntroduction  Traffic generators  Testing  Hardware – complex, strong, expensive  Software – free, modular  UrBBaN-Gen  Arhitecture for behaviour based traffic generation  Developed for complex services (e.g., Massively Multiplayer Online Role-Playing Games)  Basic idea – user behavior at the application level controls the parameters of the generated traffic Split, September 20124 /13

5. Department of Telecommunications UrBBaN-Gen arhitecture Zagreb, 20125 /13

6. Department of Telecommunications Linux Containers  Lightweight system virtualization mechanism  Not a virtual machine, but a virtual environment that has its own process and network space.  One traffic sender/receiver per LXC  Problems:  Stability  Scalability Split, September 20126 /13

7. Department of TelecommunicationsIMUNES  Integrated Multiprotocol Network Emulator Simulator  Charcteristics  Virtualization – FreeBSD jails  Network emulation and communication – Netgraph  Transactional file system – ZFS  Ability to create complex emulated networks – no need for network hardware (routers/switches) Split, September 20127 /13

8. Department of Telecommunications IMUNES - GUI Split, September 20128 /13

9. Department of TelecommunicationsMethodology  Comparing two testbeds  Measured  CPU load  Packet loss  Tests  Testing with fixed pps (packets per second) rate and fixed packet size, while changing the number of sender nodes.  Testing with fixed pps rate and fixed number of nodes, while changing the packet size. Split, September 20129 /13

10. Department of Telecommunications Results - CPU vs number of nodes Split, September 201210 /13

11. Department of Telecommunications Results - packet loss vs number of nodes Split, September 201211 /13

12. Department of Telecommunications Results – CPU vs packet size Split, September 201212 /13

13. Department of TelecommunicationsConclusions  How to generate accurate network traffic in a scalable way?  IMUNES as a virtualization platform  Results indicate IMUNES is more stable than LXCs, and results with lower packet loss  Future work: full integration of IMUNES with UrBBaN-Gen, distribution of one IMUNES experiment on multiple PCs Split, September 201213 /13