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 ComputingUnska 3, Zagreb, Croatia

mirko.suznjevic@fer.hr

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

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Department of TelecommunicationsOutline

¨ Problem

¨ Introduction UrBBaN-Gen IMUNES

¨ Methodology

¨ Results

¨ Conclusion

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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

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Department of TelecommunicationsUrBBaN-Gen arhitecture

Zagreb, 2012 5 /13

Department of TelecommunicationsLinux 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

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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)

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Department of TelecommunicationsIMUNES - GUI

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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.

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Department of Telecommunications

Results - CPU vs number of nodes

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Department of Telecommunications

Results - packet loss vs number of nodes

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Department of TelecommunicationsResults – CPU vs packet size

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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

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