Value-added services (e.g., overlaid video advertisements) have become an integral part of today’s content delivery networks (CDNs). To offer cost-efficient, scalable, and more agile provisioning of new value-added services in CDNs, network functions virtualization paradigm may be leveraged to allow implementation of fine-grained services as a chain of virtual network functions (VNFs) to be placed in CDN. The manner in which these chains are placed is critical as it both affects the quality of service (QoS) and provider cost. The problem is however, very challenging due to the specifics of the chains (e.g., one of their end-points is not known prior to the placement). We formulate it as an integer linear program and propose a cost efficient proactive VNF placement and chaining algorithm. The objective is to find the optimal number of VNFs along with their locations in such a manner that the cost is minimized while QoS is met. Apart from cost minimization, the support for large-scale CDNs with a large number of servers and end-users is an important feature of the proposed algorithm. Through simulations, the algorithm’s behavior for small-scale to large-scale CDN networks is analyzed.
To the best of our knowledge, the only paper to discuss a use case for VNF–based value-added service provisioning in CDN is reference @cite_19 which focuses on the architectural aspects while we focus on the algorithmic aspects. The European Telecommunications Standards Institute (ETSI) has also proposed a use case on the virtualization of CDNs entities (e.g., surrogate server, CDN controller, etc.) @cite_27 , but with no bearing on value-added service provisioning. Besides, few NFV architectures for CDN have been proposed in the literature @cite_2 @cite_22 , yet with no bearing on value-added services provisioning.
@cite_19 @cite_27 @cite_22 @cite_2
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Due to the recent surge in end-users demands, value-added video services (e.g. in-stream video advertisements) need to be provisioned in a cost-efficient and agile manner in Content Delivery Networks (CDNs). Network Function Virtualization (NFV) is an emerging technology that aims to reduce costs and bring agility by decoupling network functions from the underlying hardware. It is often used in combination with Software Defined Network (SDN), a technology to decouple control and data planes. This paper proposes an NFV and SDN-based architecture for a cost-efficient and agile provisioning of value-added video services in CDNs. In the proposed architecture, the application-level middleboxes that enable value-added video services (e.g. mixer, compressor) are provisioned as Virtual Network Functions (VNFs) and chained using application-level SDN switches. HTTP technology is used as the pillar of the implementation architecture. We have built a prototype and deployed it in an OPNFV test lab and in SAVI, a Canadian distributed test bed for future Internet applications. The performance is also evaluated. Virtualizing network functions is becoming a major trend in today's research on cloud computing. Among networking elements, the Home Gateway appears to be one with the most diverse functions to handle and thus, with great potential for virtualization. To this end, the paper proposes a solution to ease adoption by Service Providers of the latest breakthroughs in cloud computing technologies towards a virtualized Home Gateway. Although the NFV approach globally pretends bringing operational advantages in terms of CAPEX and OPEX, it is essential to prove them for Home Gateways scenarios where compatibility and versatility are strong requirements. To achieve this goal, we introduce the concept of Surrogate vNF, which makes Home Gateways NFV aware. The paper highlights a migration path towards full Home Gateway virtualization and proves its concept through a real implementation and a simulated evaluation on a practical use case related to video content distribution. In this paper we investigate synergies between Network Functions Virtualization (NFV) architectures and Software-Defined Networks (SDN). We identify value adding capabilities such technologies may offer to telecom providers regarding agile management and deployment of network functions across their infrastructures. Specifically, we propose a modular NFV architecture that permits policy-based management of Virtualized Network Functions (VNFs). Hence we can handle the lifecycle of VNFs and dynamically instantiate business applications as Service Chains of diverse VNFs delivered to large scale customers. To describe network resources, network control functions and VNFs capabilities we introduced an Information Model that abstracts these elements. In order to verify the proposed architecture we considered the case of multiple Content Delivery Network (CDN) providers having CDN caching nodes hosted by another operator. We implemented and deployed VNFs capable to map virtual links on the physical substrate and monitor the traffic of each client, ultimately providing the means to instantiate and orchestrate a policy-based traffic engineering service as a business application.