The application of data clustering algorithms in packet pair/stream dispersion probing of wired and wired-cum-wireless networks

This thesis reports a study of network probing algorithms to wired and wireless Ethernet networks. H begins with a literature survey of Ethernet and related technology, and existing research on bandwidth probing. The OPtimized Network Engineering Tool (OPNET) was used to implement a network probing testbed, through the development of packet pair/stream modules. Its performance was validated using a baseline scenario (two workstations communicating directly on a wired or wireless channel) and it was shown how two different probe packet sizes allowed link parameters (bandwidth and the inter-packet gap) to be obtained from the packet pair measurements and compared with their known values. More tests were carried out using larger networks of nodes carrying cross-traffic, giving rise to multimodal dispersion distributions which could be automatically classified using data-clustering algorithms. Further studies used the ProbeSim simulation software, which allowed network and data classification processes were brought together in a common simulation framework The probe packet dispersion data were classified dynamically during operation, and a closed-loop algorithm was used to adjust parameters for optimum measurement. The results were accurate for simple wired scenarios, but the technique was shown to be unsuitable for heterogeneous wired-cum-wireless topologies with mixed cross-traffic.