Network functionality that formerly resided in dedicated hardware appliances is in the process of being migrated to virtualized network functions (VNFs) hosted on shared infrastructure (NFVi).
Unlike physical appliances where resources are completely dedicated, virtual appliances must use shared resources which can be impacted by co-resident VMs. In fact, it has already been proven that all of the largest cloud providers are vulnerable to significant performance degradation in such shared environments. While various strategies are employed to isolate VNF resources to ensure performance and scale, each of these strategies comes with certain risks and trade-offs.
This white paper explains those isolation strategies, and why they might not work as intended.