  Network virtualization enables computing networks and data center (DC)
providers to manage their networking resources in a flexible manner using
software running on physical computers. In this paper, we address the existing
issues with the classic DC network topologies in virtualized environment, and
investigate a set of DC network topologies with the capability of providing
dynamic structures according to the service-level required by the active
traffic in a virtual DC network. In particular, we propose three main
approaches to modify the structure of a classic BCube topology as a topology
benchmark, and investigate their associated structural features and maximum
achievable interconnected bandwidth for different routing scenarios. Finally,
we run an extensive simulation program to check the performance of the proposed
modified topologies in a simulation environment which considers failure
analysis and also traffic congestion. Our simulation experiments, which are
consistent to our design goals, show the efficiency of the proposed modified
topologies comparing to the classic BCube in terms of bandwidth availability
and failure resiliency.
