In this dissertation, we study methods for improving the routing performance
of computer communication networks in dynamic environments. The dynamic environments
we considered in this work include both network topology changes and
traffic demand changes.
In the first part, We propose a novel fast rerouting scheme for link state routing
protocols. Link state routing protocols are widely used by todayâÂÂs ISPs on their
backbone networks. The global update based rerouting of link state protocols usually
takes seconds to complete which affects real time applications like Voice over IP.
In our scheme, usually, only routers directly connected to failed links are involved
in rerouting. For other cases, only a small number of neighboring routers are also
involved. Since our scheme calculates rerouting paths in advance, rerouting can be
done faster than previous reactive approaches. The computation complexity of our
scheme is less than previous proactive approaches.
In the second part, we study Multihoming Route Control (MRC) that is a technology
used by multihomed stub networks recently. By selecting ISPs with better
quality, MRC can improve routing performance of stub networks significantly.
We first study the stability issue of distributed MRC and propose two methods
to avoid possible oscillations of traditional MRC. The first MRC method is based on âÂÂoptimal routingâÂÂ. The idea is to let the stub networks belonging to a same
organization coordinate their MRC and thus avoid oscillations. The second method
is based on âÂÂuser-optimal routingâÂÂ. The idea is to allow MRC devices to use multiple
paths for traffic to one destination network and switch traffic between paths smoothly
when path quality or the traffic matrix changes.
A third MRC method we propose is for MRC of traffic consisting of TCP flows
of different sizes on paths with bottlenecks of limited capacity. Based on analysis of
quality characteristics of bottleneck links, we propose a greedy MRC approach that
works in small timescales. Simulation results show that the proposed MRC method
can greatly improve routing performance for the MRC sites as well as the overall
routing performance of all sites in the network.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/4745 |
| Date | 25 April 2007 |
| Creators | Liu, Yong |
| Contributors | Reddy, A. L. Narasimha |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | 1416471 bytes, electronic, application/pdf, born digital |
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