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

Assessment testing can be used to inform policy decisions : the case of Jordan

Over the past two decades, the Jordanian education system has made significant advances. Net enrollment in basic education increased from 89 percent in 2000 to 97 percent in 2006. Transition rates to secondary education increased from 63 to 79 percent in the same period. At the same time, Jordan made significant gains on international surveys of student achievement, with a particularly impressive gain of almost 30 points on the science portion of the Third International Mathematics and Science Study. Changes in test scores over time are presented and analyzed using decomposition analysis. The trends are related to policy changes over time. It is argued that benchmarking education systems and constant feedback between researchers and policymakers contributed to this achievement.Tertiary Education,Education For All,Teaching and Learning,Secondary Education,Primary Education

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

Evaluation of Fire Effects on Reinforced Concrete Columns Using Finite Element Method

International audienceIn this paper, four different Reinforced Concrete (RC) columns are analyzed with Finite Element (FE) ABAQUS software and validated experimentally. One of the RC columns, the control specimen, is subjected to only compressive force applied at both ends of the column, while the other three models were loaded under both compressive force and fire load. The temperature is applied to reach up to 600 Celsius Degree for the period of 10, 15 and 20 min. The load-displacement diagrams were constructed. Results showed good correlations between experimental and FE analysis. Moreover, results showed reduction in load capacity as duration of fire load increases

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

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

Plasticity-Damage Bounding Surface Model for Concrete Under Cyclic-Multiaxial Loading.

Concrete exhibits a significant strain-softening behavior beyond the peak stress, and moreover, the mechanism of inelastic deformation in concrete consists of both plastic slip and microcracking. Hence, a combined plasticity and damage mechanics model is proposed for modeling concrete behavior under both multiaxial monotonic and cyclic loadings. The model adopts a bounding surface concept for both plasticity and damage. The introduced plasticity bounding surface is a function of the maximum compressive strain experience by the material, while the damage bounding surface is a function of the accumulated damage parameter. By this definition, both surfaces shrink in size in the stress space consistently with strain and damage. In this model, the material parameters are identified by fitting well-documented test data. The functional dependence of the material parameters on stress history, \varepsilon\sb{\rm max}, and damage parameter allow realistic modeling of the complex cyclic behavior of concrete. The proposed model combines plastic strain with strain due to damage, which account for softening behavior of concrete. Plastic strain components are calculated by using the plastic modulus which is a function of the distance from the current stress point to the bounding surface along the deviatoric stress direction S\sb{\rm ij}. Similarly, damage growth rate is obtained by the hardening modulus which is a function of the distance defined above. The hardening behavior of concrete is assumed herein to be controlled by both damage and plasticity, while the strain softening regime is controlled by damage processes only. The simultaneous use of the plasticity surface and the damage surface, leads to a constitutive model that accounts for the essential features of concrete such as pressure sensitivity, shear compaction-dilatancy, and stiffness degradation. Comparison of model predictions with the available experimental data has been made and the results show good agreement. The model is computationally efficient and appears promising for implementation in generalized finite element programs