Friday May 17, 2013

Network QoS Simulator on the NetBeans Platform

qSim is a computer network simulator with emphasis on Quality of Service (QoS) mechanisms. It lets you observe how computer networks react to different QoS mechanisms, including network node usage (input/output queues, RX/TX buffers usage), data flow delay time, and packet drop statistics.

13 QoS mechanisms are supported, which can be divided in three groups: packet classification & marking, active queue management, and packet scheduling algorithms.

The network topology is fully customizable, including:

  • link bit rate and length (in meters)
  • link reliability
  • simulation of input/output queues
  • simulation of RX/TX buffers
  • size of all buffers/queues
  • different data flows (TCP/UDP/ICMP protocols supported, various packet sizes, realistic packet generation delays)

The simulations have been tested and compared with real CISCO devices, with positive results.

qSim was developed at the Faculty of Informatics and Information Technologies, Slovak University of Technology, in Bratislava.


Geertjan Wielenga (@geertjanw) is a Principal Product Manager in the Oracle Developer Tools group living & working in Amsterdam. He is a Java technology enthusiast, evangelist, trainer, speaker, and writer. He blogs here daily.

The focus of this blog is mostly on NetBeans (a development tool primarily for Java programmers), with an occasional reference to NetBeans, and sometimes diverging to topics relating to NetBeans. And then there are days when NetBeans is mentioned, just for a change.


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