Conference paper Open Access
J. Martín-Pérez; Carlos J. Bernardos
Network Services (NS) like video streaming are usually made up of several Network Functions (NF) that compose a Service Function Chain (SFC). Examples of these NFs can be firewalls, video optimizers, parental control, etc.; and they can be virtualized (becoming Virtual Network Functions, VNFs) using Network Function Virtualization (NFV) technologies.
When a NS deployment is requested, an algorithm must decide where to map the SFC in the infrastructure satisfying the imposed link and computational requirements. This is known as the VNF mapping problem, which is NP-hard  and can be solved using techniques as Integer Linear Programming (ILP), Mixed ILP (MILP)  ; and heuristic algorithms  .
None of the cited solutions to the problem deal with a multi- domain scenario, i.e. an environment where multiple Service Providers (SPs) share resources to perform NS deployments. This work presents how we solve the VNF mapping problem when multiple SPs are involved, and asses the performance of several greedy algorithms we have tried.