The Internet traffic is constantly increasing following the emergence of new network
applications like social networks, peer-to-peer, IP phone or IP television. In addition,
these new applications request better path availability and path quality.
Indeed the efficiency of these applications is strongly related to the quality of the underlying network.
In that context network operators make use of traffic engineering techniques
in order to improve the quality of the routes inside their network, but also
to reduce the network cost of increased traffic handling with a better utilization of existing resources.
This PhD thesis covers several topics of Traffic Engineering and
Fast Restoration in IP/MPLS networks.
Our first contribution is related to the definition of a well-engineered network. In the literature
mathematical formulation of Traffic Engineering (TE) requirements are very diverse.
We have thus performed a comparative study of many objective functions, in order to differentiate them and
choose in a rational way the one that best reflects Traffic Engineering goals.
We have also designed a method approaching optimal TE, whereby we divide
the traffic matrix in N sub-matrices and route them independently, based on the derivatives of the objective function.
The second topic addressed in this work concerns link weight optimizers (LWOs).
Link weight optimization is the traffic engineering {it "standard"} technique in networks running
link state routing protocols (which are widely used in transit networks).
These link weight optimizers suffer from several limitations due to the BGP (Border Gateway Protocol) Hot-Potato
rule, which is basically not considered by such optimizers.
Therefore we have proposed a BGP-aware link weight optimization method that takes problematic Hot-Potato effects
into account, and even turns them into an advantage. We have also studied how LWOs
behave in big networks which have to use BGP route reflectors. Finally we have studied
whether forwarding loops can appear or not when traffic is split among multiple
equivalent egress routers, an optional BGP feature that we did use in our Hot-Potato aware LWO.
Our last contribution concerns network resilience. We have proposed a solution for a rapid recovery from a link or node failure
in an MPLS network. Our solution allows a decentralized deployment combined with a minimal bandwidth usage while requiring only
reduced amount of information to flood in the network. This
method is the first that makes possible a decentralized deployment combined
with an optimal resource consumption.
To easily simulate and test the methods proposed in this work, we have also contributed to the development of TOTEM - a
TOolbox for Traffic Engineering Methods.
| Identifer | oai:union.ndltd.org:BICfB/oai:ETDULg:ULgetd-01212009-135757 |
| Date | 07 November 2008 |
| Creators | Balon, Simon |
| Contributors | WOLPER, Pierre, LEDUC, Guy, BONAVENTURE, Olivier, FORTZ, Bernard, GUERIN, Roch, BOUTABA, Raouf |
| Publisher | Universite de Liege |
| Source Sets | Bibliothèque interuniversitaire de la Communauté française de Belgique |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://bictel.ulg.ac.be/ETD-db/collection/available/ULgetd-01212009-135757/ |
| Rights | unrestricted, Je certifie avoir complété et signé le contrat BICTEL/e remis par le gestionnaire facultaire. |
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