83,565 research outputs found
The Role of Inter-Controller Traffic for Placement of Distributed SDN Controllers
We consider a distributed Software Defined Networking (SDN) architecture
adopting a cluster of multiple controllers to improve network performance and
reliability. Besides the Openflow control traffic exchanged between controllers
and switches, we focus on the control traffic exchanged among the controllers
in the cluster, needed to run coordination and consensus algorithms to keep the
controllers synchronized. We estimate the effect of the inter-controller
communications on the reaction time perceived by the switches depending on the
data-ownership model adopted in the cluster. The model is accurately validated
in an operational Software Defined WAN (SDWAN). We advocate a careful placement
of the controllers, that should take into account both the above kinds of
control traffic. We evaluate, for some real ISP network topologies, the delay
tradeoffs for the controllers placement problem and we propose a novel
evolutionary algorithm to find the corresponding Pareto frontier. Our work
provides novel quantitative tools to optimize the planning and the design of
the network supporting the control plane of SDN networks, especially when the
network is very large and in-band control plane is adopted. We also show that
for operational distributed controllers (e.g. OpenDaylight and ONOS), the
location of the controller which acts as a leader in the consensus algorithm
has a strong impact on the reactivity perceived by switches.Comment: 14 page
Energy-aware routing in multiple domains software defined networks
The growing energy consumption of communication networks has attracted
the attention of the networking researchers in the last decade. In this context,
the new architecture of Software-Defined Networks (SDN) allows a flexible
programmability, suitable for the power-consumption optimization problem.
In this paper we address the issue of designing a novel distributed routing
algorithm that optimizes the power consumption in large scale SDN with
multiple domains. The solution proposed, called DEAR (Distributed Energy-
Aware Routing), tackles the problem of minimizing the number of links that can
be used to satisfy a given data traffic demand under performance constraints
such as control traffic delay and link utilization. To this end, we present
a complete formulation of the optimization problem that considers routing
requirements for control and data plane communications. Simulation results
confirm that the proposed solution enables the achievement of significant energy
savings.Peer ReviewedPostprint (published version
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