Over the course of the last year, NFVI and VIM architectural deployments have not changed dramatically, and still primarily confirm to two different models. However, we expect to see increased focused on a Core + Edge model, as 5G and IoT take hold and the Edge becomes the new battleground for NFV deployments.
For use cases like vIMS, a centralized cloud is adequate, as there is little need to have extensive services or compute capabilities close to the subscribers. In general, where latency and bandwidth are not major issues for the application, a centralized cloud will be easier to manage and cheaper to deploy.
Core DC + Edge
The edge could be the Central Office in the case of thin CPE (i.e. the customer premise equipment is simply providing dumb connectivity) or the customer premise with thick clients (customer premise equipment that is able to host a few virtual machines).
Multi-access Edge Computing (MEC) is another use case where the cloud will likely be split between the core data center and the edge. MEC is an ETSI ISG that works on providing IT and cloud-computing capabilities within the Radio Access Network close to mobile users. The goal is to provide services close to the subscriber where requirements such as: low latency, big data analytics/ machine learning, location aware services and services that need network context are important.