Algorithms for functionalities of virtual network: a survey

Nowadays, network functionalities are provided through dedicated hardware middleboxes. These hardware middleboxes are statically embedded with network topology to provide the network services. The types of middleboxes increase in the network, with an increased number of users and network services. The growth in multiple kinds of middleboxes creates an ossified network that is difficult for network management. Network Function Virtualization (NFV) deals with such problems by eliminating network functions from the piece of hardware and implement it as a software to execute in a commodity server. The network virtualization provides more flexibility and elasticity in the network to automatically manage and control the network functions. NFV internally implements the different algorithms to automate the on-demand service provisioning mechanism. In the service provisioning process, NFV allows to share the physical resources among the Virtual Network Functions (VNFs). In order to optimally allocate the physical resources to each VNF, there is a need to include some efficient resource sharing mechanisms in NFV infrastructure. These resource sharing mechanisms are the VNF placement, service chaining, VNFs scheduling, and VNF migration. Therefore, this survey discusses the solutions, implementation tools, and limitations with respect to these resource sharing mechanisms. Moreover, research challenges and current trends related to the resource sharing strategies are explored.