Enhancing Trust and Resource Allocation in Telecommunications Cloud

Network Functions Virtualization (NFV) has brought the telecommunications industry multiple benefits; however, it has also introduced many new security issues. This thesis tackles security issues related to NFV trust and defines trust as confidence in the integrity of the software and hardware in a system. Existing NFV trust solutions have added trust to the NFV infrastructure with boot time measurements, placement of Virtualized Network Functions (VNFs) on trusted infrastructure and integrity checks of a small set of VNF operations. This thesis implements the introduced trust elements from existing solutions and proposes several extensions. These extensions enable trust in the NFV management software with run time measurements, introduces a new method for building VNF trust, extends the number of trusted VNF operations and increases the user auditability of trust decisions. The proposed extensions are designed, implemented and evaluated in a trusted NFV cloud environment. Although the proposed extensions create a more trusted cloud, they come at a steep performance cost to VNF operations. However, the most impacted VNF operations only affect the cloud provider and not the telecommunications consumer. This thesis offers a valuable contribution to NFV clouds where increased trust is more important than maximized performance or where VNF operations are rarely performed

VNF-AAPC : accelerator-aware VNF placement and chaining

In recent years, telecom operators have been migrating towards network architectures based on Network Function Virtualization in order to reduce their high Capital Expenditure (CAPEX) and Operational Expenditure (OPEX). However, virtualization of some network functions is accompanied by a significant degradation of Virtual Network Function (VNF) performance in terms of their throughput or energy consumption. To address these challenges, use of hardware-accelerators, e.g. FPGAs, GPUs, to offload CPU-intensive operations from performance-critical VNFs has been proposed. Allocation of NFV infrastructure (NFVi) resources for VNF placement and chaining (VNF-PC) has been a major area of research recently. A variety of resources allocation models have been proposed to achieve various operator's objectives i.e. minimizing CAPEX, OPEX, latency, etc. However, the VNF-PC resource allocation problem for the case when NFVi incorporates hardware-accelerators remains unaddressed. Ignoring hardware-accelerators in NFVi while performing resource allocation for VNF-chains can nullify the advantages resulting from the use of hardware-accelerators. Therefore, accurate models and techniques for the accelerator-aware VNF-PC (VNF-AAPC) are needed in order to achieve the overall efficient utilization of all NFVi resources including hardware-accelerators. This paper investigates the problem of VNF-AAPC, i.e., how to allocate usual NFVi resources along-with hardware-accelerators to VNF-chains in a cost-efficient manner. Particularly, we propose two methods to tackle the VNF-AAPC problem. The first approach is based on Integer Linear Programming (ILP) which jointly optimizes VNF placement, chaining and accelerator allocation while concurring to all NFVi constraints. The second approach is a heuristic-based method that addresses the scalability issue of the ILP approach. The heuristic addresses the VNF-AAPC problem by following a two-step algorithm. The experimental evaluations indicate that incorporating accelerator-awareness in VNF-PC strategies can help operators to achieve additional cost-savings from the efficient allocation of hardware-accelerator resources

Algorithms for advance bandwidth reservation in media production networks

Media production generally requires many geographically distributed actors (e.g., production houses, broadcasters, advertisers) to exchange huge amounts of raw video and audio data. Traditional distribution techniques, such as dedicated point-to-point optical links, are highly inefficient in terms of installation time and cost. To improve efficiency, shared media production networks that connect all involved actors over a large geographical area, are currently being deployed. The traffic in such networks is often predictable, as the timing and bandwidth requirements of data transfers are generally known hours or even days in advance. As such, the use of advance bandwidth reservation (AR) can greatly increase resource utilization and cost efficiency. In this paper, we propose an Integer Linear Programming formulation of the bandwidth scheduling problem, which takes into account the specific characteristics of media production networks, is presented. Two novel optimization algorithms based on this model are thoroughly evaluated and compared by means of in-depth simulation results

Security and trust in a Network Functions Virtualisation Infrastructure

L'abstract è presente nell'allegato / the abstract is in the attachmen

Availability-driven NFV orchestration

Virtual Network Functions as a Service (VNFaaS) is a promising business whose technical directions consist of providing network functions as a Service instead of delivering standalone network appliances, leveraging a virtualized environment named NFV Infrastructure (NFVI) to provide higher scalability and reduce maintenance costs. Operating the NFVI under stringent availability guarantees is fundamental to ensure the proper functioning of the VNFaaS against software attacks and failures, as well as common physical device failures. Indeed the availability of a VNFaaS relies on the failure rate of its single components, namely the physical servers, the hypervisor, the VNF software, and the communication network. In this paper, we propose a versatile orchestration model able to integrate an elastic VNF protection strategy with the goal to maximize the availability of an NFVI system serving multiple VNF demands. The elasticity derives from (i) the ability to use VNF protection only if needed, or (ii) to pass from dedicated protection scheme to shared VNF protection scheme when needed for a subset of the VNFs, (iii) to integrate traffic split and load-balancing as well as mastership role election in the orchestration decision, (iv) to adjust the placement of VNF masters and slaves based on the availability of the different system and network components involved. We propose a VNF orchestration algorithm based on Variable Neighboring Search, able to integrate both protection schemes in a scalable way and capable to scale, while outperforming standard online policies

Will SDN be part of 5G?

For many, this is no longer a valid question and the case is considered settled with SDN/NFV (Software Defined Networking/Network Function Virtualization) providing the inevitable innovation enablers solving many outstanding management issues regarding 5G. However, given the monumental task of softwarization of radio access network (RAN) while 5G is just around the corner and some companies have started unveiling their 5G equipment already, the concern is very realistic that we may only see some point solutions involving SDN technology instead of a fully SDN-enabled RAN. This survey paper identifies all important obstacles in the way and looks at the state of the art of the relevant solutions. This survey is different from the previous surveys on SDN-based RAN as it focuses on the salient problems and discusses solutions proposed within and outside SDN literature. Our main focus is on fronthaul, backward compatibility, supposedly disruptive nature of SDN deployment, business cases and monetization of SDN related upgrades, latency of general purpose processors (GPP), and additional security vulnerabilities, softwarization brings along to the RAN. We have also provided a summary of the architectural developments in SDN-based RAN landscape as not all work can be covered under the focused issues. This paper provides a comprehensive survey on the state of the art of SDN-based RAN and clearly points out the gaps in the technology.Comment: 33 pages, 10 figure

NFV Platforms: Taxonomy, Design Choices and Future Challenges

Due to the intrinsically inefficient service provisioning in traditional networks, Network Function Virtualization (NFV) keeps gaining attention from both industry and academia. By replacing the purpose-built, expensive, proprietary network equipment with software network functions consolidated on commodity hardware, NFV envisions a shift towards a more agile and open service provisioning paradigm. During the last few years, a large number of NFV platforms have been implemented in production environments that typically face critical challenges, including the development, deployment, and management of Virtual Network Functions (VNFs). Nonetheless, just like any complex system, such platforms commonly consist of abounding software and hardware components and usually incorporate disparate design choices based on distinct motivations or use cases. This broad collection of convoluted alternatives makes it extremely arduous for network operators to make proper choices. Although numerous efforts have been devoted to investigating different aspects of NFV, none of them specifically focused on NFV platforms or attempted to explore their design space. In this paper, we present a comprehensive survey on the NFV platform design. Our study solely targets existing NFV platform implementations. We begin with a top-down architectural view of the standard reference NFV platform and present our taxonomy of existing NFV platforms based on what features they provide in terms of a typical network function life cycle. Then we thoroughly explore the design space and elaborate on the implementation choices each platform opts for. We also envision future challenges for NFV platform design in the incoming 5G era. We believe that our study gives a detailed guideline for network operators or service providers to choose the most appropriate NFV platform based on their respective requirements. Our work also provides guidelines for implementing new NFV platforms