NFV Management and Orchestration in Large-Scale Distributed Systems

Network Functions Virtualization (NFV) radically transforms the way network operators design and manage network services, promising a lot of potential benefits such as agility, flexibility, reduction of CAPEX and OPEX. It eliminates the dependency between the network function software and hardware enabling pure-software based network function that runs on commodity hardware, called Virtualized Network Function (VNF). NFV, along with other emerging technologies such as Software-Defined Networking (SDN), enables network operators to create dynamic and programmable network services, wherein VNFs are deployed on-demand, dynamically chained and optimized over time to cope with emerging business needs. The European Telecommunications Standards Institute (ETSI) developed the NFV Management and Orchestration (MANO) framework, which consists of Virtualized Infrastructure Manager (VIM), VNF Manager (VNFM) and NFV Orchestrator (NFVO), in order to provide network operators with the sophisticated capabilities needed to manage the dynamic aspects of infrastructure, VNFs and network services. This thesis elaborates and addresses key architectural and algorithmic research challenges related to the NFV management and orchestration in distributed and large-scale systems. We look at orchestration scalability from an architectural perspective and propose to leverage two-layer hierarchical service orchestration to manage network services over distributed infrastructure. We also propose an architecture of Virtual Network Platform-as-a-Service (VNPaaS) that utilizes the hierarchical orchestration to offer next-generation mobile networks as-a-service. The architecture is illustrated by offering the 3GPP Home Subscriber Server (HSS) as-a-Service (HSSaaS), in which the HSS is decomposed into VNFs with a granularity finer than what is known today. On the algorithmic side, a key challenge is to identify the number and location of the NFVO and VNFM functional blocks since they have a significant impact on the overall system cost and performance, among others. In particular, we tackle the online placement of VNFM to enable network operators to adjust the number and location of VNFMs in response to variation in workload. There, we assume a fixed location of NFVO and aim at minimizing the operational cost. Owing to its complexity, we propose a tabu search heuristic and numerically show that it is faster than the mathematical formulation by many orders of magnitude. We further study the joint placement of NFVO and VNFM. We first address the problem in the context of the multi-orchestrator system and seek to minimize the number of NFVOs and VNFMs. We mathematically formulate the problem and propose a two-step placement heuristic to solve the problem efficiently. Finally, we investigate the same problem in the context of single- and multi-orchestrator systems providing a comparative study of the worst-case delay in both scenarios. We also propose a late acceptance hill-climbing heuristic to solve the problem in a reasonable time frame

NFV Orchestrator Placement for Geo-Distributed Systems

The European Telecommunications Standards Institute (ETSI) developed Network Functions Virtualization (NFV) Management and Orchestration (MANO) framework. Within that framework, NFV orchestrator (NFVO) and Virtualized Network Function (VNF) Manager (VNFM) functional blocks are responsible for managing the lifecycle of network services and their associated VNFs. However, they face significant scalability and performance challenges in large-scale and geo-distributed NFV systems. Their number and location have major implications for the number of VNFs that can be accommodated and also for the overall system performance. NFVO and VNFM placement is therefore a key challenge due to its potential impact on the system scalability and performance. In this paper, we address the placement of NFVO and VNFM in large-scale and geo-distributed NFV infrastructure. We provide an integer linear programming formulation of the problem and propose a two-step placement algorithm to solve it. We also conduct a set of experiments to evaluate the proposed algorithm.Comment: This paper has been accepted for presentation in 16th IEEE International Symposium on Network Computing and Applications (IEEE NCA 2017

An Architecture for QoS-Enabled Mobile Video Surveillance Applications in a 4G EPC and M2M Environment

© 2016 IEEE. Mobile video surveillance applications are used widely nowadays. They offer real-time video monitoring for homes, offices, warehouses, airports, and so on with live and pre-recorded on-demand video streaming. Quality of service (QoS) remains a key challenge faced by most of these applications. In this article, we propose an architecture for mobile video surveillance applications with a guaranteed and differentiated QoS support. The architecture relies on the 3GPP 4G evolved packet core (EPC). The main components are the QoS enabler, media server, and machine-to-machine gateway and surveillance application. To demonstrate its feasibility, a proof of concept prototype has been implemented and deployed. We also took measurements to evaluate the performance. Several lessons were learned. For instance, multimedia frameworks must allow for buffering controls in media streaming to reduce live streaming delay. In addition, we have learned that publicly available materials related to the EPC prototyping platform we have used (i.e., OpenEPC) are scarce. This has made our prototyping task rather difficult

A Virtual Network PaaS for 3GPP 4G and Beyond Core Network Services

Cloud computing and Network Function Virtualization (NFV) are emerging as key technologies to overcome the challenges facing 4G and beyond mobile systems. Over the last few years, Platform-as-a-Service (PaaS) has gained momentum and has become more widely adopted throughout IT enterprises. It simplifies the applications provisioning and accelerates time-to-market while lowering costs. Telco can leverage the same model to provision the 4G and beyond core network services using NFV technology. However, many challenges have to be addressed, mainly due to the specificities of network services. This paper proposes an architecture for a Virtual Network Platform-as-a-Service (VNPaaS) to provision 3GPP 4G and beyond core network services in a distributed environment. As an illustrative use case, the proposed architecture is employed to provision the 3GPP Home Subscriber Server (HSS) as-a-Service (HSSaaS). The HSSaaS is built from Virtualized Network Functions (VNFs) resulting from a novel decomposition of HSS. A prototype is implemented and early measurements are made.Comment: 7 pages, 6 figures, 2 tables, 5th IEEE International Conference on Cloud Networking (IEEE CloudNet 2016

Towards HSS as a virtualized service for 5G networks

© 2015 IFIP. Home Subscriber Server (HSS) is the main database of the current generation\u27s cellular communications systems. It contains subscriber-related information, such as the authentication information and the list of services to which each user is subscribed. The anticipated tremendous increase in the number of subscribers, services and devices (M2M) in 5G networks brings new challenges with regard to HSS provisioning. It calls for more scalability and elasticity regarding information storage, access and management. The current method for increasing the number of HSSs deployed is certainly not the most cost efficient solution. On the other hand, advanced virtualization techniques can aid in tackling the challenges while enabling a smooth migration to 5G. This paper proposes a new architecture for a scalable and elastic HSS using virtualization. The new architecture enables easy and rapid deployment of new HSS instances at a minimal cost, while increasing efficiency of the use of resources. The paper presents the architecture, demonstrates its use via a case scenario, describes the implemented proof of concept prototype and evaluates the performance results

Ensuring Reliability and Low Cost When Using a Parallel VNF Processing Approach to Embed Delay-Constrained Slices

© 2004-2012 IEEE. Slices were introduced in 5G to enable the co-existence of applications with different requirements on a single infrastructure. Slices may be delay-constrained for mission-critical applications such as Tactile Internet applications. When delay-constrained slices are implemented as collections of virtual network function (VNF) chains, a key challenge is to place the VNFs and route the traffic through the chains to meet a strict delay constraint. Parallel VNF processing has been proposed as a promising approach. However, this approach increases the number of physical nodes in the chains, and thus decreases the reliability, which is also critical for Tactile Internet applications. Furthermore, the cost depends upon the specific VNF placement and traffic routing, as nodes and links are heterogeneous. This article tackles the issues of reliability and cost when embedding delay-constrained slices. We model the problem as an optimization problem that minimizes reliability degradation and cost while ensuring the strict delay constraint when a parallel VNF processing approach is used. Due to the complexity of the formulated problem, we also propose a Tabu search-based algorithm to find sub-optimal solutions. The results indicate that our proposed algorithm can significantly improve cost and reliability while meeting a strict delay constraint

A 3GPP 4G Evolved Packet Core-Based System Architecture for QoS-Enabled Mobile Video Surveillance Applications

Mobile video surveillance systems are ubiquitous nowadays and are used in both civilian and military settings such as public safety and security. They are real-time Machine-to-Machine (M2M) video applications that consume a large amount of network bandwidth and are sensitive to delay, jitter and packet loss. Evolved Packet Core (EPC) is the new core network for the next generation network. It enables the design and implementation of new innovative applications that are aware of data flows. It also enables services provisioning with both guaranteed and differentiated end-to-end Quality of Service (QoS). This thesis proposes a novel RESTful web services based system architecture for mobile video surveillance applications over EPC. The proposed architecture enables mobile video services provisioning with guaranteed and differentiated QoS, something which is not possible in the state-of-the-art. The main component of the architecture is a Service Delivery Platform (SDP), made up of a QoS enabler and a streaming enabler. The QoS enabler exposes EPC network resources and QoS capabilities in order to allow the surveillance application to provide differentiated QoS to various end-users. The streaming enabler enables live and on-demand video streaming as well as video recording for later viewing. The SDP components (i.e. QoS enabler and streaming enabler) can be accessed via Representational State Transfer (REST) interface. In addition, a proof of concept prototype has been implemented deployed to demonstrate the feasibility of the proposed architecture. Performance measurements have also been made to evaluate the viability of the architecture