An SDN QoE Monitoring Framework for VoIP and video applications

Τα τελευταία χρόνια έχει σημειωθεί ραγδαία άνοδος του κλάδου των κινητών επικοινωνιών, αφού η χρήση των κινητών συσκευών εξαπλώνεται με ταχύτατους ρυθμούς και αναμένεται να συνεχίσει τη διείσδυσή της στην καθημερινότητα των καταναλωτών. Το γεγονός αυτό, σε συνδυασμό με τους περιορισμούς που θέτει η τρέχουσα δομή των δικτύων επικοινωνιών, καθιστά αναγκαία την ανάπτυξη νέων δικτύων με αυξημένες δυνατότητες, ώστε να είναι δυνατή η εξυπηρέτηση των χρηστών με την καλύτερη δυνατή ποιότητα εμπειρίας και ταυτόχρονα τη βέλτιστη αξιοποίηση των πόρων του δικτύου. Μία νέα δικτυακή προσέγγιση αποτελεί η δικτύωση βασισμένη στο λογισμικό (Software Defined Networking - SDN), η οποία αφαιρεί τον έλεγχο από τις συσκευές προώθησης του δικτύου, και οι αποφάσεις λαμβάνονται σε κεντρικό σημείο. Η ποιότητα υπηρεσίας που αντιλαμβάνεται ο χρήστης, ή αλλιώς ποιότητα εμπειρίας, κρίνεται ζήτημα υψηλής σημασίας στα δίκτυα SDN. Η παρούσα διπλωματική εργασία έχει ως στόχο την παρουσίαση της τεχνολογίας SDN, την επισκόπηση της υπάρχουσας έρευνας στο πεδίο της ποιότητας εμπειρίας σε SDN δίκτυα και στη συνέχεια την ανάπτυξη μίας SDN εφαρμογής η οποία παρακολουθεί και διατηρεί την ποιότητας εμπειρίας σε υψηλά επίπεδα για εφαρμογές VoIP και video. Πιο συγκεκριμένα, η εφαρμογή SQMF (SDN QoE Monitoring Framework) παρακολουθεί περιοδικά στο μονοπάτι μετάδοσης των πακέτων διάφορες παραμέτρους του δικτύου, με βάση τις οποίες υπολογίζει την ποιότητα εμπειρίας. Εάν διαπιστωθεί ότι το αποτέλεσμα είναι μικρότερο από ένα προσδιορισμένο κατώφλι, η εφαρμογή αλλάζει το μονοπάτι μετάδοσης, και έτσι η ποιότητα εμπειρίας ανακάμπτει. Η δομή της παρούσας διπλωματικής εργασίας είναι η εξής: Στο κεφάλαιο 1 παρουσιάζεται η σημερινή εικόνα των δικτύων επικοινωνιών και οι προβλέψεις για τη μελλοντική εικόνα, καθώς και οι προκλήσεις στις οποίες τα σημερινά δίκτυα δε θα μπορούν να αντεπεξέλθουν. Στη συνέχεια στο κεφάλαιο 2 περιγράφεται αναλυτικά η τεχνολογία SDN ως προς την αρχιτεκτονική, το κύριο πρωτόκολλο που χρησιμοποιεί, τα σενάρια χρήσης της, την προτυποποίηση, τα πλεονεκτήματα και τα μειονεκτήματά της. Το κεφάλαιο 3 εισάγει την έννοια της ποιότητας εμπειρίας του χρήστη και παραθέτει ευρέως γνωστά μοντέλα υπολογισμού της για διάφορους τύπους εφαρμογών, που χρησιμοποιούνται στην παρούσα εργασία. Σχετικές υπάρχουσες μελέτες στο πεδίο της ποιότητας εμπειρίας σε δίκτυα SDN αλλά και συγκριτικός πίνακας μπορούν να βρεθούν στο κεφάλαιο 4. Τα επόμενα κεφάλαια αφορούν στην εφαρμογή SQMF που υλοποιήθηκε στα πλαίσια της παρούσας διπλωματικής εργασίας: το κεφάλαιο 5 περιγράφει αναλυτικά όλα τα προαπαιτούμενα εργαλεία και οδηγίες για την ανάπτυξη του SQMF, ενώ το κεφάλαιο 6 παρουσιάζει παραδείγματα όπου η ποιότητα εμπειρίας ενός δικτύου μπορεί να υποστεί μείωση. Τέλος, το κεφάλαιο 7 αναλύει σε βάθος τις σχεδιαστικές προδιαγραφές, τη λογική και τον κώδικα του SQMF και παρέχει επίδειξη της λειτουργίας του και αξιολόγησή του, ενώ το κεφάλαιο 8 συνοψίζει επιγραμματικά τα συμπεράσματα της παρούσας εργασίας και ανοιχτά θέματα για μελλοντική έρευνα.Lately, there has been a rapid rise of the mobile communications industry, since the use of mobile devices is spreading at a fast pace and is expected to continue its penetration into the daily routine of consumers. This fact, combined with the limitations of the current communications networks’ structure, necessitates the development of new networks with increased capabilities, so that users can be served with the best possible quality of service and at the same time with the optimal network resources utilization. A new networking approach is Software Defined Networking (SDN) which decouples the control from the data plane, transforming the network elements to simple forwarding devices and making decisions centrally. The quality of service perceived by the user, or quality of experience (QoE), is considered to be a matter of great importance in software defined networks. This diploma thesis aims at presenting SDN technology, reviewing existing research in the field of QoE on SDN networks and then developing an SDN application that monitors and preserves the QoE for VoIP and video applications. More specifically, the developed SDN QoE Monitoring Framework (SQMF) periodically monitors various network parameters on the VoIP/video packets transmission path, based on which it calculates the QoE. If it is found that the result is less than a predefined threshold, the framework changes the transmission path, and thus the QoE recovers. The structure of this diploma thesis is the following: Chapter 1 presents the current state of communications networks and predictions for the future state, as well as the challenges that current networks will not be able to cope with. Chapter 2 then describes in detail the SDN technology in terms of architecture, main control-data plane communication protocol, use cases, standardization, advantages and disadvantages. Chapter 3 introduces the concept of QoE and lists well-known QoE estimation models for various applications types, some of which were used in this thesis. Relevant existing studies in the field of QoE on SDN networks as well as a comparative table can be found in chapter 4. The following chapters concern the framework implemented in the context of this diploma thesis: Chapter 5 describes in detail all the required tools and instructions for the development of SQMF, while Chapter 6 presents examples where the QoE in a network can face degradation. Finally, Chapter 7 analyzes in depth SQMF's design principles, logic and code files, provides a demonstration of its operation and evaluates it, whereas Chapter 8 briefly summarizes the conclusions and of this thesis and future work points

Toward Open and Programmable Wireless Network Edge

Increasingly, the last hop connecting users to their enterprise and home networks is wireless. Wireless is becoming ubiquitous not only in homes and enterprises but in public venues such as coffee shops, hospitals, and airports. However, most of the publicly and privately available wireless networks are proprietary and closed in operation. Also, there is little effort from industries to move forward on a path to greater openness for the requirement of innovation. Therefore, we believe it is the domain of university researchers to enable innovation through openness. In this thesis work, we introduce and defines the importance of open framework in addressing the complexity of the wireless network. The Software Defined Network (SDN) framework has emerged as a popular solution for the data center network. However, the promise of the SDN framework is to make the network open, flexible and programmable. In order to deliver on the promise, SDN must work for all users and across all networks, both wired and wireless. Therefore, we proposed to create new modules and APIs to extend the standard SDN framework all the way to the end-devices (i.e., mobile devices, APs). Thus, we want to provide an extensible and programmable abstraction of the wireless network as part of the current SDN-based solution. In this thesis work, we design and develop a framework, weSDN (wireless extension of SDN), that extends the SDN control capability all the way to the end devices to support client-network interaction capabilities and new services. weSDN enables the control-plane of wireless networks to be extended to mobile devices and allows for top-level decisions to be made from an SDN controller with knowledge of the network as a whole, rather than device centric configurations. In addition, weSDN easily obtains user application information, as well as the ability to monitor and control application flows dynamically. Based on the weSDN framework, we demonstrate new services such as application-aware traffic management, WLAN virtualization, and security management

The CASPER user-centric approach for advanced service provisioning in mobile networks

Abstract This paper presents an overview of the project CASPER, 1 a 4-year Marie Curie Research and Innovation Staff Exchange (RISE) project running between 2016 and 2020, describing its objectives, approach, architecture, tools and key achievements. CASPER combines academic and industrial forces towards leveraging the expected benefits of Quality of Experience (QoE) exploitation in future networks. In order to achieve that, a QoE orchestrator has been proposed which implements the basic functionalities of QoE monitoring, estimation and management. With means of simulation and testbed emulation, CASPER has managed to develop a proprietary SDN Controller, which implements QoE-based traffic rerouting for the challenging scenario of HTTP adaptive video streaming, leading to more stable and higher QoE scores compared to a state-of-the-art SDN Controller implementation

Literature review software defined networking for VoIP, SDN

Se realizó un análisis de implementaciones de redes SDN enfocándonos a redes con servicios VoIP. Se identificaron implementaciones con OpenFlow como base, así como implementaciones con enfoques de virtualizacion de servicios SIP. Actualmente, el uso de SDN con VoIP se utiliza para permitir un control de QoS y QoE de manera dinámica, eficaz y con bajo coste de implementación. Por último, se analizaron desarrollos de SDN enfocados a seguridad, CAC (Call Admisión Control) y enfoques a la gestión de recursos.An analysis of implementations of SDN networks was carried out, focusing on networks with VoIP services. Implementations with OpenFlow as a base were identified, as well as implementations with approaches to virtualization of SIP services. Currently the use of SDN with VoIP is used to allow QoS and QoE control in a dynamic, efficient way and with low implementation cost. Finally, SDN developments focused on security, CAC (Call Admission Control) and approaches to resource management were analyzed

Quality of Service Oriented Access Point Selection Framework for Large Wi-Fi Networks

This paper addresses the problem of Access Point (AP) selection in large Wi-Fi networks. Unlike current solutions that rely on Received Signal Strength (RSS) to determine the best AP that could serve a wireless user’s request, we propose a novel framework that considers the Quality of Service (QoS) requirements of the user’s data flow. The proposed framework relies on a function reflecting the suitability of a Wi-Fi AP to satisfy the QoS requirements of the data flow. The framework takes advantage of the flexibility and centralised nature of Software Defined Networking (SDN). A performance comparison of this algorithm developed through an SDN-based simulator shows significant achievements against other state of the art solutions in terms of provided QoS and improved wireless network capacity

Developing an SDWN Architecture for Wireless Network Engineering to Support a Quality of Experience Aware Handover

The massive growth of data consumption and the variety of wireless technology emergence has made the handover (HO) an attractive research topic nowadays, mainly due to the popularity of Wireless Local Area Networks (WLANs), which allow users to reach high-speed data communication while they are in movement. Moreover, mobile devices such as tablets and smartphones have also become increasingly popular due to their low cost and ease of use, and an increase in mobile device use is expected to accelerate in the coming years, along with the availability and use of applications such as real-time services and online gaming. The traditional HO methods will likely not meet the requirements of mobile devices for modern applications due to the lack of intelligence, lack of awareness Quality of Service (QoS) and Quality of Experience (QoE) requirements of mobile users. We, therefore, introduce a novel architecture that supports horizontal HO in homogenous networks. This architecture is based on the Software-Defined Wireless Networking (SDWN) concept, where the wireless network is controlled centrally and the wireless Access Points (APs) are programmable. In this architecture, HO algorithms will assist wireless users to find the network that could best support the application requirements through Quality of Service (QoS) and Quality of Experience (QoE) management policies. The first HO algorithm proposed in this thesis is called Quality of Experience Oriented Handover Algorithm. This algorithm will guarantee the best possible connectivity to the users in terms of their QoE and QoS requirements and outperforms the traditional methods in a sparse network environment. The second contribution is called Optimised Handover Algorithm for Dense WLAN Environments. This algorithm has been designed to address dense network environments via taking into consideration the Adaptive Hysteresis Value (AHV). The AHV will help the Optimised Handover Algorithm via reducing the so-called ping-pong effect. This contribution shows promising performance results by selecting the best candidate AP, decreasing the number of redundant HO and avoiding the ping-pong effect. The final contribution is called Priority Based Handover Algorithm. We extended our proposed SDWN architecture in order to include the concept of prioritising users and make a smart decision during the process of HO. This algorithm will prioritise a certain class of users to avoid the effect of the over-congestion. The results show that the approach based on priority outperforms the state of the art and provides better QoE to the high priority users despite the over-congestion situation

Specification of Smart AP solutions - version 2

This document includes the specification of the second version of the Smart Access Point (AP) Solutions, which are being developed within WP3 of the Wi-5 project. After the Literature Review, a global view of the Wi-5 architecture is presented which includes not only the Smart AP Solutions but also the Cooperative Functionalities being developed in WP4. Next, the Smart AP Solutions are described including the summary of the general approach being followed based on Light Virtual APs (LVAPs). The functionalities enabling Radio Resource Management (i.e. Dynamic Channel Allocation, Load Balancing and Power Control) are reported in detail and the current status of the implementation of the solutions is detailed, with a set of improvements aimed at integrating the support of different channels within the Wi-5 framework. A multi-channel handoff scheme has been designed, requiring a good synchronisation between the different events, in order to make the LVAP switching happen at the same moment when the STA switches its channel. In addition, the beacon generation has been modified in order to improve the scalability and to give a better user experience during handoffs. Tests measuring the handoff delay are presented using three wireless cards from different manufacturers, and using as test traffic a flow of an online game with real-time constraints. The results show that fast handovers ranging from 30 to 200 milliseconds can be achieved. The savings provided by frame aggregation, and its effect on subjective quality have also been studied. A methodology including subjective tests with real users has evaluated this effect, using paired comparison. The results indicate that bandwidth usage savings and especially significant packet rate reduction can be obtained without degrading players’ Quality of Experience (QoE), as long as the overall latency is kept under 100ms. An important finding coming from these results is that the players do not register delay variation introduced by multiplexing