M Tech Dissertations

Permanent URI for this collectionhttp://ir.daiict.ac.in/handle/123456789/3

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    Performance analysis of fair schedulers under heterogeneous traffic
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2005) Changela, Jasankumar R.; Jotwani, Naresh D.
    In this thesis, the role of the packet scheduling discipline has been studied in providing QoS over the Internet. The fairness and scalability requirements expected to be satisfied by the scheduling discipline have been analysed, with reference to the two categories under which schedulers are broadly classified: Round-robin-based schedulers and Timestamp-based schedulers. In particular, the basic principles and design goals of three specific Fair Schedulers WDRR, NestedDRR and StratifiedRR have been studied. The Network Simulator (ns-2) tool has been enhanced to support WDRR, NestedDRR and StratifiedRR schedulers. To analyse the performance of WDRR, NestedDRR and StratifiedRR under MPEG, CBR and BE traffic, simulations have been carried out for specific load conditions under single hop and two hop topologies. From simulation results it has been observed that, as its reserved rate increases, MPEG traffic achieves better performance under StratifiedRR. Also, degradation in the performance received by other contending traffics is greater under StratifiedRR. It has been identified that, for fixed value of Load Factor, as quantum increases, the End-to-End delay and End-to-End delay-jitter of MPEG traffic under WDRR show greater variation than that seen under NestedDRR. Based on these results, an improvement over StratifiedRR has been proposed which is expected to make the delay and delay-jitter seen by a flow independent of the packet sizes in other flows.
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    ItemOpen Access
    Study of MPLS traffic engineering with constraint-based routing
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2004) Modi, Bhavesh; Maitra, Anutosh
    Multi-protocol Label Switching (MPLS) is fast becoming popular for future communication networks running applications demanding high speed and Quality of Service. In this work, we have studied the evolution of MPLS, various issues related to MPLS and the architecture ofMPLS. The simplicity and functional capabilities ofMPLS enables various important applications over it such as Virtual Private Networks, Provisioning of Quality of Service and Traffic Engineering. The traffic engineering perspective of MPLS is studied in a greater detail as MPLS protocol has certain advantageous features in traffic engineering applications, the major being that it allows explicit routing, through which separately calculated routes can be specified for different traffic flows. The process of route calculation can be automated with the help of Constraint-based Routing. The thesis also presents a study on Constraint-based routing in MPLS environment. After that, a few classical constraint-based routing algorithms that consider bandwidth as constraint are investigated. The effectiveness of these algorithms is ascertained by means of simulation results. The concept of minimum interference routing and the corresponding algorithm MIRA is studied in greater detail in this work and presented in the thesis. The performance of MIRA was analyzed and factors that affect the performance were identified. Finally, the work suggests two modifications over MIRA based on the observations and analysis mentioned above. The primary philosophy behind the modifications are identifying the criticality of the resources and quantifying the order of the criticality. The performance of the suggested modified algorithms is benchmarked against classical MIRA algorithm and the simulation results are presented.