VIRTUAL CACHE & VIRTUAL WAN ACCELERATOR FUNCTION PLACEMENT FOR COST-EFFECTIVE CONTENT DELIVERY SERVICES

The algorithm to determine the place where network functions are located and how much capacities of network function flexibly are required is essential for economical NFV (Network Functions Virtualization)- based network design. The authors proposed a placement algorithm of virtual routing function and virtual firewall function in the NFV-based network for minimizing the total network cost and developed the effective allocation guidelines for these virtual functions. This paper proposes an NFV-based virtual cache placement algorithm for cost-effective content delivery service such as video streaming, which judges the optimal placement of the cache per content, not on a virtual machine (VM) like the conventional CDN (virtual CDN). Moreover, the content is dynamically cached at the time of first content delivery like ICN (Information-Centric Networking) without placing the cache in advance like CDN .Our evaluation results revealed that the proposed algorithm could reduce total network costs by about 15% compared with CDN .Even if the content cache is deployed economically, performance will degrade if the latency between the content cache and user terminals is long. In order to prevent such a case, this paper also propose a cost-effective placement method of NFV-based WAN accelerator function.