Traffic Control for Multi-homed End-hosts via Software Defined Networking Anees Mohsin Hadi Al-Najjar B.Sc. (Computer Science), M.Sc. (Computer Science) A thesis submitted for the degree of Doctor of Philosophy at The University of Queensland in 2019 School of Information Technology & Electrical Engineering Abstract Software Defined Networking (SDN) is an emerging technology that allows computer networks to be more efficiently managed and controlled by providing a high level of abstraction and network programmability. Having powerful abstractions and pro- grammability via a centralised network controller provides new potential improve- ments to computer networks, such as easier network management, faster innovation and reduced cost. SDN has been successfully applied in wide area and data centre networks, and has achieved a significant improvement in network performance and efficiency. However, using SDN to control network traffic in end-host devices has not been investigated thoroughly. The research presented in this thesis aims to address this gap and inves- tigates the potential benefits of SDN for end-hosts. This thesis explores the feasibility of applying the SDN methodology to control network traffic on multi-homed end de- vices. The objective was to create a control mechanism by changing the network stack on the client in a way that is transparent to the application layer, the network infras- tructure, and other hosts on the network. In contrast to other solutions such as MPTCP, which require a protocol stack upgrade on all the participating nodes, the approach presented in this thesis allows quick and easy client-side-only deployment. This thesis presents an architecture for embedding SDN components, i.e. the SDN controller and switch, on multi-homed devices, and its use for traffic control. The simultaneous use of multiple network interfaces was explored and utilised for the im- plementation and evaluation of various load balancing algorithms. In order to do effective load balancing, it is important to know the state of the various host interfaces and related links, in particular the link capacity. To enable this, the thesis also presents an approach to monitor and measure link capacity, which is tightly integrated with the SDN traffic control architecture. For this purpose, the method of Variable Packet size (VPS) probing was adapted to work in the SDN context on end- hosts. The approach of SDN-based traffic control and load balancing was extensively evalu- ated for two specific use cases, web traffic and Voice over IP (VoIP), considering differ- i ent transport layer protocols. Our experimental evaluation has shown the feasibility of the proposed method, and has demonstrated its potential for improving the Quality of Experience (QoE) for end-users. The experiments have shown that our SDN-based approach can even outperform MPTCP, even though MPTCP has the advantage of controlling both end points of the communication. ii Declaration by author This thesis is composed of my original work, and contains no material previously pub- lished or written by another person except where due reference has been made in the text. I have clearly stated the contribution by others to jointly-authored works that I have included in my thesis. I have clearly stated the contribution of others to my thesis as a whole, including sta- tistical assistance, survey design, data analysis, significant technical procedures, pro- fessional editorial advice, financial support and any other original research work used or reported in my thesis. The content of my thesis is the result of work I have car- ried out since the commencement of my higher degree by research candidature and does not include a substantial part of work that has been submitted to qualify for the award of any other degree or diploma in any university or other tertiary institution. I have clearly stated which parts of my thesis, if any, have been submitted to qualify for another award. I acknowledge that an electronic copy of my thesis must be lodged with the University Library and, subject to the policy and procedures of The University of Queensland, the thesis be made available for research and study in accordance with the Copyright Act 1968 unless a period of embargo has been approved by the Dean of the Graduate School. I acknowledge that copyright of all material contained in my thesis resides with the copyright holder(s) of that material. Where appropriate I have obtained copyright per- mission from the copyright holder to reproduce material in this thesis and have sought permission from co-authors for any jointly authored works included in the thesis. iii Publications during candidature [1] Anees Al-Najjar, Siamak Layeghy, and Marius Portmann, Pushing SDN to the End-host, Network Load Balancing using OpenFlow, in Proceedings of the Interna- tional Conference on Pervasive Computing and Communication Workshops (PerCom Workshops). IEEE, 2016, pp. 1−6. [2] Anees Al-Najjar, Farzaneh Pakzad, Siamak Layeghy, and Marius Portmann, Link Capacity Estimation in SDN-based End-hosts, in Proceedings of the 10th Interna- tional Conference on Signal Processing and Communication Systems (ICSPCS). IEEE, 2016, pp. 1−8. [3] Anees Al-Najjar, Samuel Teed, Jadwiga Indulska, and Marius Portmann, Flow- based Load Balancing of Web Traffic using OpenFlow, in Proceedings of the 27th International Telecommunication Networks and Applications Conference (ITNAC). IEEE, 2017, pp. 1−6. [4] Anees Al-Najjar, Siamak Layeghy, Marius Portmann, and Jadwiga Indulska, Enhancing Quality of Experience of VoIP Traffic in SDN based End-hosts, in Proceedings of the 28th International Telecommunication Networks and Applications Conference (ITNAC). IEEE, 2018, pp. 1−8. [5] Anees Al-Najjar, Marius Portmann, Siamak Layeghy, and Jadwiga Indulska, Flow-level Load Balancing of HTTP Traffic using OpenFlow, Australian Journal of Telecommunications and the Digital Economy, vol. 6, pp. 75-95, 2018. iv Publications included in this thesis [1] Anees Al-Najjar, Siamak Layeghy, and Marius Portmann, Pushing SDN to the End- host, Network Load Balancing using OpenFlow, in Proceedings of the International Conference on Pervasive Computing and Communication Workshops (PerCom Work- shops). IEEE, 2016, pp. 1−6. Contributor Statement of contribution Author Anees Al-Najjar (Candidate) Conception and design (90%) Analysis and interpretation (90%) Drafting and production (85%) Author Siamak Layeghy Drafting and production (5%) Author Marius Portmann Conception and design (10%) Analysis and interpretation (10%) Drafting and production (10%) [2] Anees Al-Najjar, Farzaneh Pakzad, Siamak Layeghy, and Marius Portmann, Link Capacity Estimation in SDN-based End-hosts, in Proceedings of the 10th Interna- tional Conference on Signal Processing and Communication Systems (ICSPCS). IEEE, 2016, pp. 1−8. Contributor Statement of contribution Author Anees Al-Najjar (Candidate) Conception and design (90%) Analysis and interpretation (90%) Drafting and production (85%) Author Farzaneh Pakzad Drafting and production (5%) Author Siamak Layeghy Drafting and production (5%) Author Marius Portmann Conception and design (10%) Analysis and interpretation (10%) Drafting and production (5%) v [3] Anees Al-Najjar, Samuel Teed, Jadwiga Indulska, and Marius Portmann, Flow- based Load Balancing of Web Traffic using OpenFlow, in Proceedings of the 27th International Telecommunication Networks and Applications Conference (ITNAC). IEEE, 2017, pp. 1−6. Contributor Statement of contribution Author Anees Al-Najjar (Candidate) Conception and design (90%) Analysis and interpretation (85%) Drafting and production (85%) Author Samuel Teed Conception and design (5%) Author Jadwiga Indulska Analysis and interpretation (5%) Drafting and production (5%) Author Marius Portmann Conception and design(5%) Analysis and interpretation (10%) Drafting and production (10%) [4] Anees Al-Najjar, Siamak Layeghy, Marius Portmann, and Jadwiga Indulska, En- hancing Quality of Experience of VoIP Traffic in SDN based End-hosts, in Proceed- ings of the 28th International Telecommunication Networks and Applications Confer- ence (ITNAC). IEEE, 2018, pp. 1−8. Contributor Statement of contribution Author Anees Al-Najjar (Candidate) Conception and design (95%) Analysis and interpretation (90%) Drafting and production (80%) Author Siamak Layeghy Drafting and production (10%) Author Marius Portmann Conception and design (5%) Analysis and interpretation (5%) Drafting and production (5%) Author Jadwiga Indulska Analysis and interpretation (5%) Drafting and production (5%) vi [5] Anees Al-Najjar, Marius Portmann, Siamak Layeghy, and Jadwiga Indulska, Flow-level Load Balancing of HTTP Traffic using OpenFlow, Australian Journal of Telecommunications and the Digital Economy, vol. 6, pp. 75-95, 2018. Contributor Statement of contribution Author Anees Al-Najjar (Candidate) Conception and design (95%) Analysis and interpretation (90%) Drafting and production (80%) Author Siamak Layeghy Drafting and production (5%) Analysis and interpretation(5%) Author Marius Portmann Conception and design (5%) Analysis and interpretation (5%) Drafting and production (10%) Author Jadwiga Indulska Drafting and production (5%) vii Contributions by others to the thesis A/Prof Marius Portmann and Prof Jadwiga Indulska provided valuable guidance and feedback during conducting this research and contributed in the conception, design, interpretation and drafting parts of the work. Statement of parts of the thesis submitted to qualify for the award of another degree