PhD Defence by Bogdan Andrus

SDN/NFV Control Plane Optimizations for Fixed-Mobile Access and Data Center Optical Networking

Principal supervisor:  Professor Idelfonso Tafur Monroy, DTU Fotonik
Co-supervisor: Dr. Juan José Vegas Olmos, Mellanox Technologies
Co-supervisor: Dr. Achim Autenrieth, ADVA Optical Networking
Co-supervisor: Dr. Michael Eiselt, ADVA Optical Networking

Evaluation Board:
Associate Professor José Soler, DTU Fotonik
Professor Lena Wosinska, KTH Stockholm, Sweden
Associate Professor Fernando Kuipers, Delft University of Technology, the Netherlands

Master of the Ceremony

Associate Professor Ying Yan, DTU Fotonik



This thesis seeks to leverage SDN and NFV technologies to enable scalable, high performance, resilient and cost effective Fixed-Mobile Convergence (FMC) on three separate segments: access/aggregation, inter but also intra data center (DC) networks for distributed Next Generation Points of Presence (NG-POP - the location in the operator infrastructure centralizing the IP edge for all access types).


From a structural stand point, shared access/aggregation for data transport solutions (i.e., low latency optical cross connects and Wavelength Division Multiplexed-Passive Optical Networks) are proposed, evaluated  and assessed for compatibility with the stringent bandwidth, latency and jitter requirements for baseband mobile, fixed and Wi-Fi services. Functional convergence is achieved by integrating universal network functions like Authentication, Data Path Management, content caching inside the NG-POP with the help of SDN and NFV techniques. Comprehensive convergence is demonstrated, for the first time to our knowledge, through the study of a series of use cases highlighting the FMC impact on user experience: seamless authentication and roaming through various network access points (i.e., Wi-Fi, mobile, fixed) as well as improved QoS and network utilization through content caching. To provide survivability for NG-POPs, Network Function live migration with zero downtime is demonstrated as a prevention mechanism for infrastructure failure.


High performance scalable DCs are required by NG-POPs for providing services like content caching, multi-tenancy support, customer applications among others. To develop compatible, cost effective DC solutions, we investigate new high radix DC topologies (i.e., hypercube, fat tree, torus, jellyfish) as well as optimizing control plane operations by adopting SDN. We demonstrate that, for a high performing topology like hypercube, SDN can achieve a 45\% throughput increase, as opposed to conventional Spanning Tree Protocol.  Optimizing elastic optical network control plane for DC connections, is another aspect investigated in this work. We propose a modular scalable flexi-grid optical domain controller based on Finite State Machines and a NETCONF/YANG standard northbound interface. The modular structure allows either a centralized or a distributed deployment for on the fly encrypted device management connections. Controller evaluation over networks ranging from 1 to 64 ROADMs show a relatively constant start up and synchronization time in both deployments.These results, together with a modest log scale growth of media channel set up time, validate the scalability of our controller.


fre 24 nov 17
13:30 - 16:30


DTU Fotonik


Lyngby Campus
Bld./aud.: 341/22