Preventing Data Leakage and Traffic Optimization in Software-Defined Programmable Networks

In a distributed Software Defined Networking (SDN) architecture, the Quality of Service (QoS) experienced by a traffic flow through an SDN switch is primarily dependant on the SDN controller to which that switch is mapped. We propose a new controller-quality metric known as the Quality of Controller (QoC) which is defined based on the controller's reliability and response time. We model the controller reliability based on Bayesian inference while its response time is modelled as a linear approximation of the M/M/1 queue. We develop a QoC-aware approach for solving (i) the switch-controller mapping problem and, (ii) control traffic distribution among the mapped controllers. Each switch is mapped to multiple controllers to enable resilience with the switch-controller mapping and control traffic distribution based on the QoC metric which is the combined cost of controller reliability and response time. We first develop an optimization programming formulation that maximizes the minimum QoC among the set of controllers to solve the above problem. Since the optimization problem is computationally prohibitive for large networks, we develop a heuristic algorithm - Qoc-Aware switch-coNTroller Mapping (QuANTuM) - that solves the problem of switch-controller mapping and control traffic distribution in two stages such that the minimum of the controller QoC is maximized. Through simulations, we show that the heuristic results are within 18% of the optimum while achieving a fair control traffic distribution with a QoC min-max ratio of up to 95%.

There is a lack of high-speed and low-cost wireless network at sea to meet the increasing need of maritime users. With this observation, we have envisaged a WiMAX mesh network for high-speed ship- to-ship/shore communications. Analysis of interference range in such maritime WiMAX mesh networks is presented in this paper. And based on the findings, scheduling transmission of MAC control messages and data packets within three-hop neighborhood is investigated for the purpose of minimizing interference. A model is developed for analysis of the interference range in maritime environment. With parameter values that are derived from measurements at sea, we show that by scheduling among three-hop neighborhood the probability a transmission being interfered by a concurrent transmission drops about 30%. Simulation results show that, with the simulation settings in this paper, by scheduling among three-hop neighborhood, the initial packet delay and the average packet delay can be reduced by about 17% and 15.6% in sea state 3.0, respectively. In sea state 6.0, the performance improvement in initial packet delay and average packet delay are about 45% and 19.3%, respectively.

This paper presents an analytical model for studying the average packet delay in optical access network based on GEPON (Gigabit Ethernet Passive Optical Network) technology. Packet delay is calculated by the use of queuing theory. At the stage of network planning, mathematical modeling techniques based on analytical models and methods of queuing theory may be used to predict the quality of service of the designed network. The indicators of quality of service are the average network packet delay and its variation (jitter). This paper proposes bounded Pareto distribution for traffic flow modeling, and a method for delay analysis based on the Kramer and Langenbach-Belz approximation. The results show that the propagation delay exceeds the queuing delay and it is the main component of the delay.

Software defined networking (SDN) is becoming increasingly prevalent for its programmability that enables centralized network configuration and management. With the growth of SDNs, a cluster of controllers cooperatively manages more and more switches/flows in a network to avoid the single-controller congestion/failure and improve the control-plane robustness. Under the architecture with multiple controllers, it is expected to minimize the maximum response time on these controllers to provide better QoS for users. To achieve this target, two previous methods are mainly used, the static scheme and the dynamic scheme. However, these methods may lead to an increase of the control-plane communication overhead/delay. In this paper, we propose to minimize the maximum response time on controllers through flow redirecting, which is implemented by installing wildcard rules on switches. We formulate the minimum controller response time problem, which takes the flow-table size and link capacity constraints into account, as an integer linear program, and prove its NP-Hardness. Two algorithms with bounded approximation factors are designed to solve this problem. We implement the proposed methods on our SDN testbed. The testing results and extensive simulation results show that our proposed algorithm can reduce the maximum controller response time by about 50%–80% compared with the static/dynamic methods under the same controller cost, or reduce the number of controllers by 30% compared with the dynamic method while preserving almost the same controller response time.

The development of protocol standards and the low cost of wireless equipment increased the number of wireless network installations in public (airports, universities campuses) and private (enterprises, homes) areas all over the world. This research effort examines the IEEE 802.11 protocol that dominates wireless local area networks (WLANs). Specifically, it investigates the performance of the Distributed Coordination Function (DCF) of ΙEEE 802.11 Medium Access Control (MAC) protocol. The objective of this thesis is to contribute in the research for the development of a simple and effective MAC sub-layer for WLANs that utilize the IEEE 802.11 protocol. Mathematical models are developed to calculate the following metrics in order to examine the performance of DCF that use Binary Exponential Backoff (BEB) algorithm: a) average packet delay per backoff stage and probability per backoff stage b) average packet delay, c) packet jitter, d) packet drop probability, e) average packet drop time, f) packet delay distribution, and g) cumulative packet delay distribution. An admission control algorithm is also presented. The proposed mathematical models are a) simple, as expressed with relatively simple mathematical relations, b) accurate, since they are validated by comparing analytical against simulation results and show that the proposed models are fairly accurate, and c) provide results in short period of time. Different scenarios of WLANs are examined to investigate the effect of DCF parameters in performance and to define the system parameters values that improve the performance of the IEEE 802.11 protocol. The analysis of metrics and the application of their outcomes to WLANs contribute in the design and development of more efficient access methods to wireless medium. The main contribution of this thesis is that packet delay is investigated thoroughly as a measure of WLAN performance.%%%%Η ανάπτυξη προτύπων για τα ασύρματα τοπικά δίκτυα σe συνδυασμό μe το χαμηλό κόστος της ασύρματης τeχνολογίας eπέτρeψe την ραγδαία eξαπλωση των ασυρμάτων δικτύων σe κοινόχρηστους και σe ιδιωτικούς χώρους όπως πανeπιστήμια, πλατeίeς, αeροδρόμια, γραφeία eπιχeιρήσeων, οικίeς, κλπ. Η παρούσα διατριβή μeλeτά το πρωτόκολλο ΙEEE 802.11 το οποίο κυριαρχeί στα ασύρματα τοπικά δίκτυα. Eιδικότeρα eρeυνά την απόδοση της κατανeμημένης διαδικασίας πρόσβασης DCF του υποeπιπέδου MAC του ΙEEE 802.11. Σκοπός της παρούσας eρeυνητικής προσπάθeιας eίναι η συμβολή στην έρeυνα για την ανάπτυξη eνός απλού και αποτeλeσματικού υποeπιπέδου πρόσβασης μέσου MAC στα ασύρματα δίκτυα που βασίζονται στο πρωτόκολλο ΙEEE 802.11. Αναπτύσσονται μαθηματικά μοντέλα για τον υπολογισμό των ακόλουθων μeτρικών για την απόδοση της διαδικασίας DCF που χρησιμοποιeί τον αλγόριθμο eκθeτικής οπισθοχώρησης ΒEΒ: α) την μέση καθυστέρηση των πακέτων ανά βαθμίδα οπισθοχώρησης και την πιθανότητα ανά βαθμίδα οπισθοχώρησης, β) την μέση καθυστέρηση των πακέτων, γ) την κατανομή των καθυστeρήσeων των πακέτων, δ) την αθροιστική κατανομή των καθυστeρήσeων, e) την διακύμανση των καθυστeρήσeων των…

A Forward Resource Reservation (FRR) scheme for Optical Burst Switching (OBS) systems which can reduce the average packet delay during burst assembly is proposed. Mathematical analysis and the simulated performance are in line and validates that average packet delay can be significantly reduced by using the proposed algorithm. The main idea of FRR is to send Burst Header Packet (BHP) before the data burst is assembled. The FRR has been applied to time based, size based and mixed time and size threshold based approaches. The average packet delay and burst sizes have been studied in the three cases.

The dynamic frame sizing algorithm is a throughput-optimal algorithm that can achieve maximum network throughput without the knowledge of arrival rates. Motivated by the need for energy-efficient communication in wireless networks, in this paper, we propose a new dynamic frame sizing algorithm, called the Greenput algorithm, that takes power allocation into account. In our Greenput algorithm, time is partitioned into frames, and the frame size of each frame is determined based on the backlogs presented at the beginning of a frame. To obtain a good delay-energy efficiency tradeoff, the key insight of our Greenput algorithm is to reduce transmit power to save energy when the backlogs are low so as not to incur too much packet delay. For this, we define a threshold parameter $T_{\max }$ (for the minimum time to empty the backlogs with maximum power allocation), and the Greenput algorithm enters the (mixed) power-saving mode when the backlogs are below the threshold. Using a large deviation bound, we prove that our Greenput algorithm is still throughput optimal. In addition to the stability result, we also perform a fluid approximation analysis for energy efficiency and average packet delay when $T_{\max }$ is very large. To show the delay-energy efficiency tradeoff, we conduct extensive computer simulations by using the Shannon formula as the channel model in a wireless network. Our simulation results show that both energy efficiency and average packet delay are quite close to their fluid approximations even when $T_{\max }$ is moderately large.

We consider the routing problem in networks with single-path routing and multicasting services. In such networks, all the single-destination traffic is transmitted over exactly one path between the origin and the destination and the multiple-destination traffic (if applicable) is transmitted over exactly one tree rooted at the origin. Examples of such networks are the conventional circuit-switched telephone networks, virtual-circuit based packet networks such as the X.25 networks, networks supporting Switched Multi-megabit Data Service (SMDS), networks supporting frame relay service (FRS), and the recently proposed B-ISDNs based on asynchronous transfer mode (ATM). We consider the problem of choosing a route/tree between every origin and its single/multiple destination(s) in a network so as to minimize the maximum link utilization. We consider the formulation of this problem as a linear integer programming problem. The emphasis of this paper is (i) to consider routing for single-destination and multiple-destination (multicast) traffic in a uniform way, (ii) to develop a near-optimal quasi-static algorithm to solve the problem, and (iii) to evaluate the efficiency and effectiveness of using the minimax criterion as a surrogate objective of other performance measures, e.g. the average packet delay. The basic approach to the algorithm development is Lagrangean relaxation. We also show that the routing decisions made by the minimax utilization routing (MUR) algorithm are within 2% of an optimal solution where the objective is to minimize the average packet delay. We also discuss issues of implementing the MUR algorithm. >

Considering the problem that the SDN controller can not fully resolve the virtual network function during the Software Defined Network (SDN) and Network Function Virtualization (NVF) collaborative deployment in the satellite network, a SDN/NFV coordination based on the three-layer satellite network is designed. The framework extends the SDN controller function and proposes the SDN controller function extension method (SDN-FE) based on LightGBM algorithm. SDN-FE has extended the functions of the original SDN controller in three aspects. One is based on LightGBM to establish a classification model for intelligent forwarding of SDN controller data packets. The second is to learn and predict VNF modification of data packets through logistic regression. The third is to design an idle state monitoring mechanism. The above method effectively enhances the control capability of the SDN controller to the network. In terms of SDN packet forwarding classification, SDN-FE is compared with existing well-known machine learning classification algorithms such as SVM, random forest, LSTM. Simulation experiments show that the SDN packet forwarding classification problem is predictable. The average accuracy of the LightGBM model in multi-classification problems is over 69%, which is better than machine learning models such as SVM and random forest. The next step is to conduct an in-depth study of the packet rule learning algorithm in VNF.

The opportunistic spectrum access in cognitive radio networks has always played a key role in improving the performance of secondary users. In this paper, we propose an optimal spectrum access strategy for multi-channel access of secondary users under multiple physical considerations. Firstly we integrate path loss and Nakagami-m fading of primary and secondary links with imperfect spectrum sensing into our model to obtain the probability that data packet is successfully transmitted. Then we introduce the M/M/1/K queueing to deduce the average packet delay under the assumption of finite-size buffer. In order to minimize the total average packet delay, the optimal probability vector for spectrum access is confirmed by genetic algorithm. Result proves that our proposed spectrum access strategy outperforms the strategies of equal probability and inverse ratio. Furthermore, according to the optimal probability vector, the total average packet loss rate is derived with one more consideration that the number of transmission attempts for automatic repeat request is fixed. Finally, numerical results illustrate the effects of referred lower-layer parameters on total average packet delay and loss rate.

The investigation of the multipath QoS-routing dynamic tensor model with quality of service guarantees over the multiple metrics is presented. The expression for modeling state of the network router interface is used for representing the average packet delay as time-varying function. The conditions of ensuring QoS for the set of metrics as the packet rate and average delay are expressed. The novelty of the model is that the network metric is a function of time, and it takes into account that the average queue length and average packet delay take their limit values after convergence time. The results of the research demonstrated that the use of the dynamic tensor model allows ensuring QoS requirements more precisely.

Popularity of Software Defined Network (SDN) technology is spreading rapidly and corporate networks are deploying to take advantages of its features. Control & Data planes are segregated in SDN and simple forwarding devices enabled with OpenFlow protocol is used to forward data planes. The responsibility of control planes are taken by controller into SDN network. The data packets are generated by source host and forwarded to destination host by seeing destination address of such packet without validating source host address. Flow of data packets is controlled by controller setting up required flow entries into flow table of forwarding devices. Initially forwarding devices do not have any security & control and they are not able to forward traffic generated by attached hosts. Data packets of attached hosts are sent to the controller by forwarding devices for generation of control packets and setup necessary flow entries into device flow table. Source IP spoofed attacks may be setup by attacker in this situation and perform different type of attacks. There are some techniques for prevention and mitigation from such attacks. In this study, we offer an analysis of available source address validation techniques for SDN environment. The study discussed various features, limitations and gaps of source address validation solutions and provided various areas in SDN Security for future research.

A shared network is largely oversubscribed by independent users who make random demands on the network. Network flow control is required for the orderly operation of the network under all potential traffic loads. This paper presents a qualitative analysis of the theory of flow control to circuit-switched and packet-switched networks and pro- ,. poses 4 complementary controls and 1 subtended control to constitute "flow control." They are traffic control, routing and delay control, congestion control, network management control, and end-end flow control. This paper introduces the concept of the "R-T function" to illustrate the synthesis of delays and routing freedoms, and to demonstrate the continuum between overload and congestion phenomena. The application of the qualitative theory of flow control to the Canadian Telephone Network is reviewed and the agreement between the theory and the practice is demonstrated. The telephone network is a prime example of a circuit-switched network which has received the benefit of extensive simulation and analytical studies, as well as a long experience to validate the conclusions reached in this paper.

Recently, the usage of Internet through mobile devices has surpassed the access through wired network. It makes extremely difficult for the network operators to manage their network in resource efficient manner. Software Defined Networking (SDN), a key 5G enabling technology, makes network management easier for the network operators through logically centralized control plane. One of the benefits of SDN is specific treatment for different network traffic type, however it requires an efficient traffic classification solution. Comprehensive research has been done on deep packet inspection or machine learning based traffic classification methods which are unsuitable for delay intolerant networks due much overhead. This paper proposes a simple traffic classification mechanism using different IP addresses which are assigned to Mobile Node (MN). Different applications in MN uses one of the assigned IP addresses based on the type of network traffic they generate. Centralized SDN controller uses these IP addresses to classify the network traffic. This method is useful for various network functions such as load balancing, security and mobility. In this paper we take mobility as a use case and through emulation results establish that traffic classification significantly improves MN mobility performance.

Software defined networks (SDN) is perceived to have specific capabilities for utilization by network infrastructures automatically. The success of OpenFlow protocol is to decouple control plane from data plane completely. However, current SDN still regards the network as a group of devices rather than a holistic resource, and traffic monitoring and control only relies on network states but not including traffic behaviours. Although speed of packet forwarding is improved significantly, QoS demands can not be satisfied when network congested, unavailability of SDN in some resource constrained scenes does not present well. To address this, we propose an application-aware traffic control scheme, in which both network states and traffic behaviours are exploited cooperatively. Deep Packet Inspection (DPI) is introduced into SDN controller. Meanwhile, a mechanism for packet classification and behaviour matching is designed. To perform information exchange between components, a publish/subscribe based middle ware is designed. Besides, mathematical models for analysing network throughput and latency are established. Simulation results show that proposed scheme can facilitate the improvement of throughput and reduce latency time of end-to-end communication.