Allocation of Virtual Cache & Virtual WAN Accelerator Functions for Cost-Effective Content Delivery Services

The algorithm to determine the place where network functions are located and how much capacities of network functions flexibly are required is essential for economical NFV (Network Functions Virtualisation)-based network design. The authors proposed an algorithm of virtual routing function and virtual firewall function allocation in the NFV-based network for minimizing the total network cost, and developed effective allocation guidelines for virtual functions. In order to minimize network cost for content delivery services such as video streaming, this paper first proposes a virtual cache placement algorithm which judges the optimal placement of the cache not on a virtual machine like vCDN (Vitualisation of CDNs) but on a content basis. Moreover, the content is dynamically cached at the time of content delivery like ICN (Information-Centric Networking) without placing the cache preliminarily like vCDN. Even if the content cache is deployed economically, performance will degrade if the latency between the content cache and the terminal increases. In order to prevent such a case, this paper also propose an cost-effective deployment method of NFV-based WAN acceleration function.