102,354 research outputs found
OpenFlow driven ethernet traffic analysis
Software Defined Networking (SDN) is a new networking paradigm that permits to slice network infrastructures. An example of SDN is the OpenFlow framework, where the control plane runs on a separate device, called controller, that manages data forwarding switches. The OpenFlow protocol ensures communications between OpenFlow switches and the OpenFlow controller. Before widely deploying OpenFlow based networks, scalability and performance of such networks should be studied and better understood. In this paper, the scalability of NOX, one of the most popular OpenFlow controller, is analyzed through both simulation and lab measurements. We perform an Ethernet trace analysis on the controller by defining flow characteristics as would be seen by an OpenFlow controller. We study the potential trace impact on an OpenFlow controller, analyzing among others, the number of flows, flow inter arrival times, traffic volumes and flow size distribution. Our results permit to discuss the feasibility of running OpenFlow networks with a single commodity PC as the controller in a mid-size campus network
On Diagnosis of Forwarding Plane via Static Forwarding Rules in Software Defined Networks
Software Defined Networks (SDN) decouple the forwarding and control planes
from each other. The control plane is assumed to have a global knowledge of the
underlying physical and/or logical network topology so that it can monitor,
abstract and control the forwarding plane. In our paper, we present solutions
that install an optimal or near-optimal (i.e., within 14% of the optimal)
number of static forwarding rules on switches/routers so that any controller
can verify the topology connectivity and detect/locate link failures at data
plane speeds without relying on state updates from other controllers. Our upper
bounds on performance indicate that sub-second link failure localization is
possible even at data-center scale networks. For networks with hundreds or few
thousand links, tens of milliseconds of latency is achievable.Comment: Submitted to Infocom'14, 9 page
Detecting Suspicious Behavior of SDN Switches by Statistics Gathering with Time
In Software Defined Network (SDN), the networks are vulnerable to attacks by compromised switches, since it often used programmable software switches are vulnerable than traditional hardware switches. Although several countermeasures against compromised switches have been proposed, the accuracy of detecting malicious behavior depends on the performance of network statistics gathering by a controller. In this paper, we propose an approach to verify the consistency of forwarding state using simultaneously network statistics gathering from the switch by accurate time scheduling. Our method enables to detect attacks by compromised switches without being influenced by the performance of statistics gathering by the controller. Our method utilizes moving average thus our method mitigates the effect on the verification accuracy from the impact of switches performance such as the error of scheduling. In addition, we implemented the proposed method with Mininet, and we confirmed that our method is able to verify without depending on the performance of statistic-gathering by the controller
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
Isolating SDN Control Traffic with Layer-2 Slicing in 6TiSCH Industrial IoT Networks
Recent standardization efforts in IEEE 802.15.4-2015 Time Scheduled Channel
Hopping (TSCH) and the IETF 6TiSCH Working Group (WG), aim to provide
deterministic communications and efficient allocation of resources across
constrained Internet of Things (IoT) networks, particularly in Industrial IoT
(IIoT) scenarios. Within 6TiSCH, Software Defined Networking (SDN) has been
identified as means of providing centralized control in a number of key
situations. However, implementing a centralized SDN architecture in a Low Power
and Lossy Network (LLN) faces considerable challenges: not only is controller
traffic subject to jitter due to unreliable links and network contention, but
the overhead generated by SDN can severely affect the performance of other
traffic. This paper proposes using 6TiSCH tracks, a Layer-2 slicing mechanism
for creating dedicated forwarding paths across TSCH networks, in order to
isolate the SDN control overhead. Not only does this prevent control traffic
from affecting the performance of other data flows, but the properties of
6TiSCH tracks allows deterministic, low-latency SDN controller communication.
Using our own lightweight SDN implementation for Contiki OS, we firstly
demonstrate the effect of SDN control traffic on application data flows across
a 6TiSCH network. We then show that by slicing the network through the
allocation of dedicated resources along a SDN control path, tracks provide an
effective means of mitigating the cost of SDN control overhead in IEEE
802.15.4-2015 TSCH networks
- …