Availability Aware SFC Embedding in NFV: A Clustering Approach
Pegah Torkamandi, Siavash Khorsandi, Bahador Bakhshi · 2019
Network Function Virtualization (NFV) was recently proposed to improve the flexibility of network service provisioning and reduce the deployment costs by the decoupling the traditional network functions from the dedicated proprietary hardware equipment and turning them into the software-based virtualized entity, which is called a Virtual Network Function (VNF). Typically, the VNFs are concatenated together in a sequential order to form a Service Function Chains (SFCs) which provide specific services for users. Since failure of each VNF leads to breaking down the entire service chain, it is critical that service providers offer guaranteed and highly available SFCs against the failures. Previous works for simplicity assumed a completely available network infrastructure or just one failure in a same time; further, they increase availability of a SFC by adding dedicated backups which is costly. Unlike previous works, we investigate the problem of guarantying the required availability of SFCs against the multiple failures in a same time with minimum resource consumption. We proposed a new Availability-aware Clustered SFC Embedding (AC-SFC) algorithm which not only satisfies the availability requirement of SFC but also reduces the footprints of backup resource by using the Share Protection Cluster (SPC). Further, this problem is formulated as an Integer Linear Programming (ILP). We proposed a heuristic algorithm to overcome the ILP's complexity and new technique for calculating the availability of SPC. The numerical results show our heuristic algorithm works efficiency and reduces the network resource consumption in different network infrastructure topologies.