Michail-Alexandros Kourtis

SDN/NFV-enabled satellite communications networks

In the context of next generation 5G networks, the satellite industry is clearly committed to revisit and revamp the role of satellite communications. As major drivers in the evolution of (terrestrial) fixed and mobile networks, Software Defined Networking (SDN) and Network Function Virtualisation (NFV) technologies are also being positioned as central technology enablers towards improved and more flexible integration of satellite and terrestrial segments, providing satellite network further service innovation and business agility by advanced network resources management techniques. Through the analysis of scenarios and use cases, this paper provides a description of the benefits that SDN/NFV technologies can bring into satellite communications towards 5G. Three scenarios are presented and analysed to delineate different potential improvement areas pursued through the introduction of SDN/NFV technologies in the satellite ground segment domain. Within each scenario, a number of use cases are developed to gain further insight into specific capabilities and to identify the technical challenges stemming from them.

SDN-based service function chaining mechanism and service prototype implementation in NFV scenario

The fast growing development of Network Function Virtualization (NFV) trends and the remarkable progress of Software Defined Networking (SDN) have yielded a synergy between both, towards the provision of convergent networking solutions. Since the traditional networking principles were not designed according to the NFV principles, a work has emerged dedicated to protocol redesign among the academic fellows and the industry representatives. A typical example that has been introduced in such eco-system is the concept of network service chaining, as a composition of virtual network functions stitched together in a logically ordered fashion, to create an integral networking service that can be owned by network administrators, programmers, cloud- and telco-operators. This appoints SDN as an essential technology enabler in administering advanced traffic steering techniques, thanks to the SDN controllers capability to dynamically manage VNFs virtual connections and underlying dataplane flows. Despite the rapid progression, the strategies for traffic steering in NFV environment, are still facing imminent challenges to be addressed. This paper joins NFV and SDN technology into a novel traffic steering solution based on open source reference implementations (such as SDK for SDN, virtual Traffic Classifier, virtual Media Transcoder, and WAN Infrastructure Connection Manager) designed with performance and network optimizations in mind. We have successfully deployed and tested the system prototype in a real datacenter. The evaluation results of the prototype system: (1) validated the presented chain use cases, (2) affirmed an efficient performance and scalability of the chaining method, and (3) certified good quality of video traffic transmission and transcoding. HighlightsHolistic approach in SFC delivery and OpenFlow-based traffic steering mechanism in OpenDaylight.Set of four components/services delivered, each of them contributing to the open source community.Implementation reference and support for all components.SFC solution deployed in SDN-NFV environment and proof of concept validated.End-to-end service chaining tests over different traffic types, to showcase a chained traffic characterization and performance implications of the same.A thorough State of the Art in standards, academic and industry implementations of SFC.

Reduced-reference video quality assessment using a static video pattern

Abstract. A reduced-reference video quality assessment (VQA) method was proposed by using structural similarity (SSIM) index as a tool to extract features from both the original and the target video sequences, using a reference video pattern. The method is suitable for monitoring the video quality in real time and across the service provision chain. The performance of the proposed method was evaluated using a large experimental set of reference and nonreference video sequences and achieves an accuracy higher than 2.56% in comparison to SSIM. Additionally, comparison to subjectively evaluated scores of Laboratory for Image and Video Engineering video quality dataset, based on difference mean opinion scores, shows that the performance of the proposed method is within the range of the full reference VQA methods.

Automated generation of VNF deployment rules using infrastructure affinity characterization

As the rollout of NFV in the Telecommunications domain gains momentum, methods that enable the automated and performant deployment of VNFs are required to support large scale deployments. This paper presents a framework that enables the automated characterization of VNFs and modelling of the relationships between resource types, quantities and achieved performance. A workload characterization approach is proposed to identify the most appropriate types of resources to be allocated to a VNF at deployment time. Machine learning modelling was used to identify the appropriate deployment configuration which meets required performance targets, such as network throughput. The proposed framework has been experimentally validated based on the optimization of a Traffic Classifier VNF deployment in an OpenStack cloud environment.

Statistical-based anomaly detection for NFV services

Large-scale, carrier-grade Network Functions Virtualisation (NFV) services are expected to involve a significant number of Virtual Network Functions, deployed across multiple Points-of-Presence (PoPs) and possibly in heterogeneous infrastructures. While proper monitoring is crucial for the commercial viability of NFV services, effectively and efficiently monitoring a huge number of VNF instances, promptly detecting any malfunctions or anomalies in order to trigger corrective actions, becomes a real challenge. This paper presents the use of an open-source monitoring system especially tailored for NFV in conjunction with statistical approaches commonly used for anomaly detection, towards the timely detection of anomalies in deployed NFV services.

T-NOVA: An Open-Source MANO Stack for NFV Infrastructures

One of the primary challenges associated with network functions virtualization (NFV) is the automated management of the service lifecycle. In this paper, we present a full software-based management and orchestration (MANO) stack which operates with OpenStack and OpenDaylight controllers and has the in-built functionality to automate the key phases of the NFV service lifecycle, namely resource discovery and matching, service mapping, service deployment, and monitoring. The MANO stack is being implemented by the EU FP7 project T-NOVA, with the components being released as open-source software. Service mapping and service deployment solutions developed in the scope of T-NOVA are presented in detail. As a proof-of-concept, we evaluate the performance of a virtualized traffic classifier network function, demonstrating the gains of virtualized hardware acceleration.

In-service Video Quality assessment based on SDN/NFV techniques

This paper discusses the utilization of SDN/NFV as enabling technology for the provision of in-service video quality assessment. The proposed method is based on a reduced reference extension of the widely used full reference SSIM metric, proving how the applicability of SDN/NFV can support the development of novel value-added service. The proposed video quality assessment method is based on a two-step process, where in the first step a test pattern is used as a reference for the assessment of the original and the degraded signal and in the second step the SSIM value is estimated by the combination of these measurements. For the validation of the proposed method, a SDN/NFV infrastructure was deployed, supporting traffic steering of selected video flows through the VNF instantiation of the proposed method. The evaluation results demonstrated the advantages in terms of agility and flexibility of the SDN/NFV combination in the provision of the proposed in-service video quality assessment methodology.

Enhancing Network Management via NFV, MEC, Cloud Computing and Cognitive Features: The “5G ESSENCE” Modern Architectural Approach

The paper work presents the essential architectural approach that has been proposed in the framework of the modern “5G-ESSENCE” EU-funded project, intending to develop a suitable ecosystem for serving real-life use cases associated to vertical industries and built on the pillars of network functions virtualisation (NFV), mobile-edge computing (MEC) capabilities, cognitive network management and appropriate use of small cells. Apart from identifying innovative features and options for enabling service deployment, the work focuses on the fundamental 5G ESSENCE-based architecture with description of the corresponding modules and their capabilities. The current approach comes as a mature continuity of previous efforts and/or related findings in the 5G-PPP context (mainly from the SESAME research project), but it purely concentrates upon providing tools for a robust and agile network management.

Service Mapping and Orchestration Over Multi-Tenant Cloud-Enabled RAN

Fifth-generation (5G) envisages a “hyper-connected society” where an enormous number of diverse entities could communicate with each other anywhere and at any time, some of which will demand extremely challenging performance requirements such as sub-millisecond latency, and higher data rates. Cloud-enabled radio access networks (CE-RANs) where intelligence is placed at the edge of the mobile network and in the proximity of end users emerge as a promising solution to improve online experience. To make CE-RAN more flexible and cost-effective, network functions virtualization and software defined networking technologies are employed, enabling features such as resource pooling, scalability, spectral efficiency, and multi tenancy. The accommodation of such technologies in the context of 5G requires multipronged efforts at various levels, in particular at the management and orchestration. Among all topics that falls into this subject, e.g., resource optimization and efficient lifecycle management, this paper focuses on two critical challenges, i.e., service mapping and quality of service assurance. Particularly, the proposed service placement solution takes into account two main constraints, i.e., quality of user experience and limited hardware capabilities available at the network edge. Simulation tools as well as the SESAME testbed have been used to extract results in this paper and a proof-of-concept evaluation is presented.

Deployment of virtual network functions over multiple WAN interconnected PoPs

Network Functions Virtualization allows Communication Service Providers to extend their traditional service portfolio to new models of service offerings, such as Virtualized Network Functions as a Service (VNFaaS), in which network functions can be traded following the “on-demand” Cloud paradigm. Incremental deployment and interoperability with legacy infrastructure, in particular Wide Area Network (WAN) domains and enterprise services, are key requirements to make this vision come true in the short/medium term. This paper discusses the main challenges that need be addressed for the adoption of VNFaaS in production environments and is particularly focused on the integration of NFV and WAN. To this end, two components are proposed: Netfloc, to support traffic steering inside NFV infrastructure points of presence, and the WAN Infrastructure Connectivity Manager (WICM), to handle the integration of virtualized network functions with WAN connectivity services, as a composed end-to-end network service.