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Improving Available Bandwidth Measurement
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| Available Bandwidth Analysis has been hindered by its ability to produce consistant results. My approach to improve the accuracy of the results is to use a Real-time operating system to improve the timing of the ICMP packet gaps. The available bandwidth tool chosen for this project is a modified bprobe/cbrobe tool. The b/cprobe tools were originally developed by Bob Carter and are maintained by the OCEANS research group at Boston University. The original tool has been modified by University of Colorado students and renamed the Available Band Width Measurement (ABWM) tool. However, the basic premise of sending a series of ICMP echo request and measuring the time gaps in the replies remains. To find out more about this project please refer to the following documents. |
| Project Proposal (draft doc file) |
| Presentation (draft ppt file) |
| Report (draft doc file) |
| Current Work This project is currently under development and have I have attemped (emphasis on attempted) several alternatives. All alternatives attempt to improve the accuracy of the sending time gaps. Previous work has shown a descepency in the requested sending times and the actual sending times, altering the time gaps and calculations which are based on the time gaps. The following approaches to using RTLinux to solve this problem have been attemped or are under current development. |
| The first attempt was running the ABWM tool under the RTLinux kernel with no changes. Source files: abwm-clean |
| The second approach was to use the the RTLinux time facilities/libraries. Source files: rt-timeonly |
| The third approach was to run the ABWM tool as a single thread under RTLinux. Source files: rt-onethread |
| The forth alternative is to run the ABWM tool under the standard Linux kernel using the alternate schedulers (sched_RR and sched_FIFO)
Source files: sched-rr |
| Real Time Linux (RTLinux) To find out more about RTLinux or to download RTLinux files, follow the following links: |
| Source files |
| Documentation |
| Examples |
| Links to Related Sites Finite State Machine Labs Inc. http://www.fsmlabs.com RTLinux.com http://www.rtlinux.com RTLinux.org http://www.rtlinux.org |
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| Linux http://www.linux.org http://www.linux.com |
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| Kernels http://www.kernel.org/ | |
| Research | |
| Oceans Group http://cs-www.bu.edu/groups/oceans/Home.html |
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| Department of Energy (DOE) Bandwidth Estimation Project http://www.caida.org/projects/bwest/ |
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| Tom Dunigan's Network Performance Links http://www.csm.ornl.gov/~dunigan/netperf/netlinks.html |
| Research by Dennis Knoop Computer Science Graduate Student University of Colorado at Colorado Springs, CO |
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| Last Updated: 18 April 2002 |