طراحي الگوريتم هاي جديد مسير يابي مبتني بر كيفيت سرويس براي مهندسي ترافيك شبكه هاي MPLS

چكيده انگليسي :

Study and Design of New QoS Routing Algorithms in MPLS Traffic Engineering Amir Alidadi a alidadi@ec iut ac ir 26th May 2009 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Mahdi Mahdavi m mahdavi@cc iut ac ir AbstractThe rapid growth and scope of multimedia applications has caused a tremendous impact on the way peoplecommunicate The mission of next generation networks NGN is facilitating multimedia applicationscreation and deployment as well as supporting interoperability and network convergence A key technology IP Multimedia Subsystem IMS is the definitive means of achieving such goals IMS has been proposed tosupport newly emerged multimedia IP based applications such as voice over IP VOIP video on demand VOD IPTV and etc using a core IP backbone Clearly such applications cause huge amount of traffic loadand require specified QoS constrains It is worth pointing out that IP protocol only provides best effortservice and use destination based routing which causes packets to reach their destination through differentpaths Since multimedia applications require specified QoS constrains IP cannot guarantee the reception ofpackets in order which is essential for the real time applications In this way traffic engineering TE is atechnique which has been used to guarantee the QoS as well as optimal use of infrastructure networks Inorder to implement TE multiprotocol label switching MPLS is the useful solution among other existingtechniques This is because MPLS packets belong to a traffic source are routed through a same path which isessential for TE implementation In addition to this MPLS is one of the crucial protocols which haveimportant rules in IMS The major technical challenge in TE is the paths selection in which both QoSconstraints and best possible resources utilization are satisfied One of the key issues in providing QoSguarantees is the paths selection where both QoS constraints and best possible resources utilization aresatisfied The problem of finding such paths is known as QoS routing and is NP complete problem ingeneral Such problems can be solved using heuristic algorithm in polynomial time Although much work hasbeen done on laying MPLS paths to optimize performance most has focused on satisfying bandwidthrequirements Relatively little research has been done on QoS routing where QoS constraints is bothbandwidth and delay In this thesis we explain QoS based routing along with MPLS and TE requirements We first propose a new Bandwidth Guarantee with Low Complexity BGLC algorithm Our simulationresults are compared with previously published algorithms which are known as MHA WSP MIRA andBCRA The simulation results reveal that BGLC presents lower rejection rate compare to the rejection rate ofMHA WSP MIRA and BCRA Furthermore the computational time of BGLC is much smaller than thosebelong to WSP MIRA and BCRA and is close to the computational time of MHA which itself presents thelowest computational time The aforementioned algorithms do not support delay constraint Hence the novelBandwidth Guarantee with Delay Guarantee BGDG algorithm is proposed The BGDG algorithm is basedon the LR Servers theory and satisfies maximum end to end delay as well as bandwidth constraint From thesimulation results of BGDG it can be stated that while BGDG guarantees the maximum end to end delay itachieves relatively proper performance Key wordsQuality of Service Traffic Engineering MPLS QoS based routing

عليدادي، امير

طراحي الگوريتم هاي جديد مسير يابي مبتني بر كيفيت سرويس براي مهندسي ترافيك شبكه هاي MPLS

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