| Summary: | Thesis (MSc)--University of Stellenbosch, 2001. === ENGLISH ABSTRACT: lP networks offer scalability and flexibility for rapid deployment of value added lP
services. However, with the increased demand and explosive growth of the Internet,
carriers require a network infrastructure that is dependable, predictable, and offers
consistent network performance.
This thesis examines the functionality, performance and implementation aspects of
the MPLS mechanisms to minimize the expected packet delay in MPLS networks.
Optimal path selection and the assignment of bandwidth to those paths for minimizing
the average packet delay are investigated.
We present an efficient flow deviation algorithm (EFDA) which assigns a small amount
of flow from a set of routes connecting each OD pair to the shortest path connecting
the OD pair in the network. The flow is assigned in such a way that the network
average packet delay is minimized. Bellman's algorithm is used to find the shortest
routes between all OD pairs. The thesis studies the problem of determining the routes
between an OD pair and assigning capacities to those routes.
The EFDA algorithm iteratively determines the global minimum of the objective function.
We also use the optimal flows to compute the optimal link capacities in both single
and multirate networks. The algorithm has been applied to several examples and to
different models of networks. The results are used to evaluate the performance of the
EFDA algorithm and compare the optimal solutions obtained with different starting
topologies and different techniques. They all fall within a close cost-performance range.
They are all within the same range from the optimal solution as well. === AFRIKAANSE OPSOMMING: lP-netwerke voorsien die skaleerbaarheid en buigsaamheid vir die vinnige ontplooing
van toegevoegde-waarde lP-dienste. Die vergrote aanvraag en eksplosiewe uitbreiding
van die Internet benodig betroubare, voorspelbare en bestendige netwerkprestasie.
Hierdie tesis ondersoek die funksionaliteit, prestasie en implementering van die MPLS(multiprotokoletiketskakel)-
meganismes om die verwagte pakketvertraging te minimeer.
Ons bespreek 'n doeltreffende algoritme vir vloei-afwyking (EFDA) wat 'n klein hoeveelheid
vloei toewys uit die versameling van roetes wat elke OT(oorsprong-teiken)-
paar verbind aan die kortste pad wat die OT-paar koppel. Die vloei word toegewys
sodanig dat die netwerk se gemiddelde pakketvertraging geminimeer word. Bellman se
algoritme word gebruik om die kortste roetes tussen alle OT-pare te bepaal. Die tesis
bespreek die probleem van die bepaling van roetes tussen 'n OT-paar en die toewysing
van kapasiteite aan sulke roetes.
Die EFDA-algoritme bepaal die globale minimum iteratief. Ons gebruik ook optimale
vloeie vir die berekening van die optimale skakelkapasiteite in beide enkel- en multikoers
netwerke. Die algoritme is toegepas op verskeie voorbeelde en op verskillende
netwerkmodelle. Die skakelkapasiteite word aangewend om die prestasie van die EFDAalgoritme
te evalueer en dit te vergelyk met die optimale oplossings verkry met verskillende
aanvangstopologieë en tegnieke. Die resultate val binne klein koste-prestasie
perke wat ook na aan die optimale oplossing lê.
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